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July 6, 2007
Eight Port, RAID 6, PCI-Express Host Adapter
A Review of the Areca ARC-1221x External Mini-SAS to PCIe SATA RAID Controller
By Arthur Whalem
Areca is shipping the ARC-1221x external dual Mini-SAS to PCI-Express SATA RAID Controller ($799). This eight channel SATA host adapter features an amazing number of RAID configurations. It supports RAID levels 0, 1, 3, 5, 6, 10 or JBOD for maximum configuration flexibility. The ARC-1221x features a PCIe eight lane interface, an 800MHz Intel IOP341 I/O processor, 256MB of on-board DDR333 533 MHz SDRAM with ECC protection and an optimized RAID engine to support extreme RAID 6 performance. It features online RAID capacity expansion, RAID level migration, hot swap, global online spare, automatic failed drive rebuilding and background RAID rebuilding.
System Requirements
Requires an available PCI-Express slot.
Supports Mac OS X 10.4.x or higher, Windows, Linux and FreeBSD.
Requires up to 8 external SATA I or SATA II 3.5" hard drives.
Dual external Mini-SAS connectors - cables not included.
PCI-Express X8 interface.
SMTP support for email notification.
Optional cables are required for 12C enclosure LEDs.
What's Included?
The Areca ARC-1221x External Mini-SAS to PCI-Express SATA II RAID controller includes a PCIe SATA host adapter, a printed users guide and a CD with software drivers and documentation.
About Areca
Areca Technology Corporation established in 1999, was founded by a group of engineers primarily from the technology institute in Taiwan. Areca designs their own custom ASIC, a high-speed IDE controller, and RAID 6 engine to achieve high data throughput. Areca provides storage products for many areas of the storage market including DAS, NAS, and SAN. All PCI, SCSI, and Fibre disk array controller's support RAID levels 0, 1, 3, 5, 6, 10 or JBOD. Areca has committed its research and development effort to disk array technologies that yield fast performance and reliability.
InstallationPCI-Express also known as PCIe, communicates using 250MB per second data lanes. PCI-Express bandwidth is determined by the number of data lanes that the device can accommodate. One lane, four lanes, eight lanes, or 16 lanes are some of the typical PCIe configurations available.
The Areca ARC-1221x SATA host adapter is an eight lane controller. The manual does not indicate if the ARC-1221x is compatible with a 4x PCIe slot. Most 8x PCIe controllers will also work in a 4x slot. By testing the ARC-1221x in an Apple Mac Pro, it was discovered that the controller will also function in a four lane PCIe configuration. However, the read performance was reduced by approximately 10% when installed in a four lane slot while testing an eight drive striped RAID set. As this is the case, I would recommend installing the ARC-1221x in an eight lane slot when possible. In an Apple Mac Pro the ARC-1221x is provided with eight lane PCIe bandwidth when installed in slot 4, which is an eight lane slot by default. Mac Pro users will need to install the mraid_macpro driver found in the PACKAGES folder on the install CD. The Mac Pro will not recognize the card without the driver installed. AMUG utilized version 1.3.1 of the ARC-1221x Mac Pro driver during this review.
Once the Areca Mac OS X driver is installed the user can open a web browser window to port 81 to configure the ARC-1221x. The browser address is formatted as http://xxx.xxx.xxx.xx:81/ with the computers IP address placed where the xxx.xxx.xxx.xx is listed. If the user is configuring the computer locally the address http://localhost:81/ can be used. The default user name is admin with a password of 0000. Once the web interface is open, the user can bookmark it for easy future access. Clicking on the "Quick Create" menu within the web interface provides the user with parameters for establishing a RAID configuration.
If the Mac Pro user would rather utilize Disk Utility to configure the hard drives attached to the ARC-1221x, the web interface can be used to set the card in JBOD mode. Clicking on the "System Config" menu and setting the JBOD/RAID configuration setting to JBOD allows Disk Utility to work with all of the hard drives mounted on the ARC-1221x.
If the ARC-1221x is set to JBOD mode all of the controllers RAID features are disabled and the hard drives are managed using Disk Utility. Most users will purchase the ARC-1221x for its RAID 6 capabilities and will want to leave the card in RAID mode. However, it is nice to know that hard drives connected to the ARC-1221x have the ability to be controlled directly by Mac OS X or the ARC-1221x RAID engine.
The Apple Mac Pro has four PCI-Express slots. It utilizes the "Expansion Slot Utility" to configure the speed of the PCIe slots. The Expansion Slot Utility can be found within Mac OS X at Macintosh HD: System:Library: CoreServices: Expansion Slot Utility. It will usually automatically launch when it detects that a card has been installed in a slot that is slower than the cards maximum speed.
When the ARC-1221x is installed in slot four of the Apple Mac Pro the Expansion Slot Utility menu looks like the image above. The Mac Pro automatically defaults to eight lanes in this configuration. Users can open the Expansion Slot Utility if they want to verify that the ARC-1221x is in an eight lane slot.
In the Mac Pro system profiler window above, PCIe slot 4 is shown. The Areca ARC-1221x is displayed in the window as a RAID Controller with a card name of "pci17d3,1280".
Cable Options
The Areca ARC-1221x provides two Mini-SAS connectors that can be configured with four different cable options. The HighPoint RocketRAID 2322 also uses these same connectors. As a result, data cables that work with the RocketRAID 2322 will also work with the Areca ARC-1221x and visa versa. The Mini-SAS connectors allow the host adapter to accommodate a wide range of SATA enclosure connections. While the ARC-1221x does not support SATA port multiplier enclosures, it does support multilane and direct connect enclosures. Cables are purchased separately based on the users enclosure configuration. Available cable models include:
1) External Mini-SAS to Infiniband (Screw) for Multilane enclosures $33.
2) External Mini-SAS to Infiniband (Latch) used with the HighPoint X4 $40.
3) External Mini-SAS to eSATA (I connector) for eSATA enclosures $59.
4) External Mini-SAS to SATA (L connector) $44.
To access all eight channels on the ARC-1221x, two external Mini-SAS cables are required. The external Mini-SAS to Infiniband cable model Ext-MS-1MSB
provides a Mini-SAS connector on one end and an Infiniband type connector on the other end. These cables allow the ARC-1221x to connect with a multilane enclosure. The EnhanceBox E8-ML SATA Multilane 8-Bay enclosure ($595) provides dual multilane connectors which makes it an excellent match for the ARC-1221x. This setup allows all eight hard drive bays inside the E8-ML enclosure to be connected with only two data cables. The ARC-1221x controller adds the redundancy of RAID 6 to the EnhanceBox E8-ML enclosure. During this review, AMUG will test the Areca ARC-1221x SATA host adapter with the EnhanceBox E8-ML.Another cable configuration that will be popular with ARC-1221x users is the external Mini-SAS to eSATA (Type I connector) cable for eSATA
enclosures. These cables allow the ARC-1221x SATA host adapter to be used with any direct connect eSATA external enclosure. The model number for this cable is Ext-MS-1MES. ARC-1221x users will need two cables to support all eight channels. Enclosures that will work with a direct connect eSATA data cable include the FirmTek SeriTek/2eEN4 eSATA 4 bay enclosure, the Addonics Disk Array with dual Disk Array 3SA, the Sonnet Fusion 400, the WiebeTech SilverSATA IV SJ 4-bay enclosure and many others. Basically, any SATA enclosure that uses eSATA data connectors and does not have a port multiplier will work with the ARC-1221x and the Mini-SAS to eSATA model Ext-MS-1MES cables.Features
The Areca ARC-1221x RAID 6 controller supports eSATA or multilane enclosures. The use of Mini-SAS allows the ARC-1221x to be compatible with many existing enclosure types. Having the ability to add RAID 6 capabilities without being required to purchase a new enclosure provides a cost effective upgrade path for existing RAID users. RAID 6 provides high reliability. It is similar to RAID 5, but performs two different parity computations. RAID 6 offers fault tolerance greater than RAID 1 or RAID 5 while utilizing the capacity of two disk drives for distributed parity data. Data is first striped on a block level across a set of disk drives. Next, a second parity set is calculated and written across all of the hard drives. This process allows RAID 6 to provide a high level of redundancy.
The eight channel ARC-1221x is powered by the Marvell 88SX6081 SATA host controller chip. The 88SC6081 Marvell chip can also be found on the HighPoint RocketRAID 2322 host adapter. In addition, the ARC-1221x also includes a high-performance 800MHz Intel IOP341 I/O processor dedicated to RAID functionality. This processor provides hardware-embedded RAID acceleration, including enhanced hardware acceleration for RAID 6. By off loading RAID calculations from the host CPU, overall system performance can be improved. The IOP341 I/O processor also supports its own ECC memory dedicated to RAID controller usage. The ARC-1221x high performance RAID 6 XOR engine can concurrently compute two parity blocks with performance very similar to RAID 5.
The Areca ARC-1221x utilizes a PCI Express 8x interface to connect up to eight SATA hard drives. The ARC-1221x allows Disk Utility to setup individual hard drives or a RAID configuration when in JBOD mode. In addition, the Areca web interface can be used to configure RAID 0, 1, 3, 5, 6 or 10. The controller provides write-through or write-back cache support, array roaming, online RAID level/stripe size migration, online capacity expansion & RAID level migration simultaneously, online volume set growth, instant availability and background initialization, automatic drive insertion / removal detection and rebuilding, hot swap, SMART (within browser), NCQ, staggered spin-up, alarm buzzer, SMTP support for email notification, is I2C & SGPIO enclosure management ready and provides upgradeable firmware. When the ARC-1221x is upgraded using the ARC1221EFI BIOS it provides Mac OS X boot capability. Drivers are available for Windows 2000/XP/Server 2003, Linux, FreeBSD, Novell Netware 6.5, Solaris 10 X86/X86_64 and Mac OS X. The Areca ARC-1221x comes with a CD and an in depth 180 page printed manual.
Not Supported
No Traditional SMART Support - While the Areca web interface can be configured to display SMART data, the driver does not pass this information to Disk Utility. As a result, Disk Utility will indicate that SMART is not supported on any volume connected to the controller. Users will need to use the Areca web interface if they want to monitor SMART data.
No Traditional Sleep Support - If the ARC-1221x is installed in a Mac Pro and no hard drives have been powered on it, then the Mac Pro can utilize sleep mode. However, if a RAID or an individual hard drive is attached or has been attached during the current power cycle the Mac Pro will not sleep properly. Restarting the computer with no hard drives powered will allow sleep mode to work once again.
Energy Usage
According to the Kill-a-Watt electricity usage monitor, the Areca ARC-1221x controller requires approximately 12 watts while idle when installed in a Mac Pro 2.66 GHz model. This was determined by measuring the energy usage with and without the card installed while the computer was idle for at least 10 minutes. The difference between the two readings is 12 watts. This controller utilizes the Intel IOP341 I/O processor which requires a little more power than most other SATA host adapters.
RAID Types
The Areca ARC-1221x provides many RAID functions that Macintosh users may not be familiar with. While Macintosh users are usually aware of the RAID 0 and RAID 1 functions provided in Disk Utility, the ARC-1221x can be used to configure several additional RAID types. These include:
RAID 3 - disk striping and complete data redundancy provided by a dedicated parity drive. RAID 3 breaks up data into smaller blocks, calculates parity by performing an exclusive-or on the blocks, and then writes the blocks to all but one drive in the array. The parity data created during the exclusive-or is then written to the last drive in the array. If only a single drive fails, the data should be recoverable.
RAID 5 - stripes data at the block level across several hard drives while distributing parity among these drives. If a single hard drive fails, a RAID 5 can usually recover using the rebuild features. If more than one drive fails the data on the RAID will be lost. This system provides redundancy with the least amount of hard drives. Backup of data is still necessary with RAID 5, but this array provides some crash protection while a striped RAID set provides none.
RAID 6 - stripes data at the block level across several hard drives. Next a dual set of parity data is calculated and distributed across all of the drives. RAID 6 is similar to RAID 5, but it performs dual parity computations. RAID 6 provides a high level of redundancy. However, if more than two drives fail, data on the RAID will be lost.
RAID 10 - creates a striped RAID set with half of the hard drives and a mirror (RAID1) of each hard drive is created so that an exact duplicate of the striped RAID set is available. This configuration can still operate with a hard drive failure. Unmounting a failed hard drive and inserting another hard drive of the same capacity or larger will allow the RAID 10 to rebuild. Any single disk can fail and no data will be lost as long as the mirror or the original disk is functional. Backup of critical files is still prudent but the redundancy of a RAID 10 disk array is very good. The Areca RAID 10 implementation offers a little more flexibility as the number of disks can be even or odd.
PerformanceThe Areca ARC-1221x was tested while installed in slot 4 of an Apple Mac Pro running Mac OS X 10.4.10. Eight 320GB Seagate 7200.10 hard drives were used to create various eight drive RAID configurations while mounted inside the EnhanceBox E8-ML. DiskTester 2.0 10GB read and write tests were performed using a run area test so that this article could display how the RAID performed. DiskTester is a Terminal application that measures the combined performance of a volume and the Mac OS X operating system. Using the command: ./disktester run-area-test --chunk-size 128M --test-size 10G --delta-percent 10 DriveName, puts DiskTester to work testing how the RAID will perform when empty, 10% full, 20% full and so on. The table below displays how the ARC-1221x performed when using RAID 5 and RAID 6 configurations.
Areca ARC-1221x - Eight Drive RAID 5 & 6 Comparison
| Area Full | write | read | write | read | write | read | write | read |
| empty | 527 | 506 | 459 | 438 | 454 | 431 | 375 | 366 |
| 10% | 530 | 506 | 460 | 435 | 457 | 434 | 382 | 363 |
| 20% | 519 | 494 | 449 | 424 | 441 | 429 | 374 | 355 |
| 30% | 502 | 482 | 437 | 416 | 434 | 411 | 363 | 346 |
| 40% | 486 | 462 | 420 | 399 | 418 | 397 | 350 | 332 |
| 50% | 457 | 446 | 397 | 380 | 396 | 379 | 307 | 316 |
| 60% | 434 | 410 | 368 | 360 | 372 | 354 | 312 | 297 |
| 70% | 408 | 386 | 349 | 334 | 348 | 331 | 290 | 278 |
| 80% | 365 | 360 | 317 | 304 | 317 | 303 | 265 | 253 |
| 90% | 324 | 308 | 268 | 268 | 277 | 265 | 233 | 223 |
| 100% | 270 | 257 | 233 | 223 | 232 | 221 | 193 | 186 |
| Average | 438 | 420 | 378 | 362 | 377 | 359 | 313 | 301 |
| Format Size | 2.04TB | 1.75TB | 1.75TB | 1.45TB | ||||
| Hot Spare | No | Yes | No | Yes | ||||
| Redundancy | Yes | Yes | Yes | Yes |
The performance results above indicate that an ARC-1221x using an eight drive Seagate 320GB 7200.10 in a RAID 5 configuration with the EnhanceBox E8-ML and an Apple Mac Pro can provide average write performance of over 430MB/sec and average read performance of 420MB/sec. Using seven hard drives to configure the RAID 5 with a hot spare reduces the average write performance to 378MB/sec. and the average read performance to 362MB/sec. This setup reduces performance by the speed of one disk drive but provides the ability to automatically rebuild the RAID 5 if a single hard drive fails.The ARC-1221x RAID 6 configuration is able to provide performance that is very similar to the RAID 5 setup with a hot spare. This is pretty amazing as RAID 6 is required to calculate an additional set of parity data and distribute it across all of the hard drives. The ARC-1221x XOR engine is able to process a single set of parity data for RAID 5 or a dual set of parity data for RAID 6 with an insignificant impact on performance levels. The 800MHz Intel IOP341 I/O processor mounted on the ARC-1221x makes this possible.
While RAID 6 provides twice the redundancy of RAID 5 some users may want to consider using an ARC-1221x RAID 6 configuration with a hot spare. This allows the RAID 6 to rebuild automatically in case of a single hard drive failure. Servers that are difficult to get to or off site may be possible candidates for hot spare usage. Hot spares setup with the ARC-1221x do not spin up until they are needed. This feature helps to keep the spare from experiencing extra wear while waiting to be used.
RAID 6 Redundancy
During this review, the RAID 6 rebuild capability of the ARC-1221x was tested. Initializing the RAID 6 volume required 4 hours and 50 minutes using eight Seagate 320GB hard drives. Larger hard drives will require additional time. Once initialized the RAID 6 volume was filled with 600GB of data. After the volume was populated with data a single hard drive was pulled to simulate a hard drive failure. The Areca web interface indicated that the RAID set was "Degraded" and displayed which hard drive had failed. The RAID 6 volume was still 1.75TB in size and fully usable. DiskTester was run to determine how performance might be impacted with a failed hard drive. The write performance of the degraded RAID 6 volume was not materially impacted by the hard drive failure. However, average read performance dropped from 359MB/sec to 194MB/sec.
Next, a second hard drive was removed from the RAID 6 volume to simulate a second hard drive failure. The RAID was still very usable. Once again write performance was minimally impacted and this time the average read performance actually rose a little to 218MB/sec. When two replacement hard drives were inserted the Areca ARC-1221x automatically started rebuilding the RAID 6 volume. The table below displays the DiskTester performance results of the original initialized RAID 6 volume and each step of the failure test plus the automatic rebuilding period.
Areca ARC-1221x - RAID 6 Drive Failure Performance Test
| Area Full | write | read | write | read | write | read | write | read |
| empty | 454 | 431 | 446 | 211 | 454 | 234 | 452 | 184 |
| 10% | 457 | 434 | 454 | 202 | 456 | 228 | 454 | 183 |
| 20% | 441 | 429 | 445 | 201 | 445 | 218 | 439 | 187 |
| 30% | 434 | 411 | 433 | 200 | 434 | 229 | 433 | 189 |
| 40% | 418 | 397 | 418 | 197 | 418 | 227 | 412 | 183 |
| 50% | 396 | 379 | 391 | 194 | 394 | 221 | 390 | 186 |
| 60% | 372 | 354 | 368 | 196 | 354 | 220 | 366 | 178 |
| 70% | 348 | 331 | 325 | 195 | 348 | 220 | 338 | 177 |
| 80% | 317 | 303 | 302 | 192 | 300 | 212 | 316 | 171 |
| 90% | 277 | 265 | 269 | 183 | 277 | 204 | 274 | 163 |
| 100% | 232 | 221 | 228 | 168 | 229 | 185 | 229 | 141 |
| Average | 377 | 359 | 371 | 194 | 373 | 218 | 373 | 177 |
| Format Size | 1.75TB | 1.75TB | 1.75TB | 1.75TB | ||||
| Hot Spare | No | No | No | No | ||||
| Redundancy | Yes | Yes | No | Yes |
The Areca ARC-1221x RAID 6 controller provides amazing stability. Pulling two hard drives from the RAID 6 volume did not significantly reduce its write performance. The read performance was reduced by approximately 46% but still provided average read performance over 190MB/sec. During the rebuilding process the RAID 6 volume was still able to provide an average of 373MB/sec. write performance and 177MB/sec. read performance. The rebuilding process slows if the RAID volume is being accessed and resumes at full speed once the volume is available. Rebuilding the RAID 6 volume with two new hard drives required 3 hours and 13 minutes. Once the RAID 6 was fully rebuilt it was able to perform at full speed with no loss of data. While users should always have a backup of important data, the redundancy provided by the ARC-1221x RAID 6 controller is very reliable and easy to use.
RAID 0 & 3
RAID users looking for maximum performance will always find that RAID 0 is the speed demon. While RAID 0 provides zero redundancy, it provides the fastest performance. Using the same eight Seagate 320GB 7200.10 hard drives, the Areca ARC-1221x configured in RAID 0 mode with the web interface was able to provide an average write speed of over 500MB/sec. and an average read speed of 479MB/sec.
Areca ARC-1221x - Eight Drive RAID 0 & 3 Comparison
| Area Full | write | read | write | read | write | read | write | read |
| empty | 608 | 578 | 607 | 498 | 523 | 500 | 459 | 430 |
| 10% | 610 | 581 | 610 | 500 | 533 | 497 | 460 | 431 |
| 20% | 595 | 564 | 594 | 505 | 520 | 497 | 447 | 426 |
| 30% | 578 | 548 | 577 | 505 | 506 | 486 | 437 | 417 |
| 40% | 558 | 526 | 558 | 508 | 487 | 471 | 420 | 401 |
| 50% | 531 | 509 | 529 | 500 | 462 | 444 | 394 | 380 |
| 60% | 500 | 469 | 500 | 473 | 437 | 412 | 375 | 356 |
| 70% | 467 | 443 | 467 | 442 | 406 | 390 | 348 | 334 |
| 80% | 426 | 405 | 426 | 401 | 370 | 354 | 319 | 303 |
| 90% | 372 | 354 | 371 | 354 | 326 | 315 | 280 | 267 |
| 100% | 310 | 295 | 310 | 294 | 270 | 260 | 233 | 223 |
| Average | 505 | 479 | 504 | 453 | 440 | 421 | 379 | 361 |
| Format Size | 2.33TB | 2.33TB | 2.04TB | 1.75TB | ||||
| Hot Spare | No | No | No | Yes | ||||
| Redundancy | No | No | Yes | Yes |
When the ARC-1221x was configured in JBOD mode and Disk Utility was used to setup the RAID 0, the read speed of the RAID was limited to approximately 508MB/sec by the Areca Mac OS X driver version 1.3.1. Using this same drive combination with the HighPoint RocketRAID 2322 and Disk Utility provides read speeds as high as 580MB/sec. and an average read performance of 480MB/sec. AMUG has notified Areca that we believe there is a bug in the JBOD implementation of the Mac OS X driver that limits striped RAID set read performance. However, as the Areca web interface can create RAID 0 arrays that provide approximately 5% higher write performance and similar read performance to the RocketRAID 2322, ARC-1221x users can easily avoid this issue.
The Areca ARC-1221x also supports RAID 3 configurations. RAID 3 provides high performance for transfer rate intensive applications and disk failure of a single device has an insignificant impact on throughput. According to our tests a RAID 3 configuration provides DiskTester results very similar to RAID 5. The ARC-1221x is the first controller that AMUG has tested that brings RAID 3 to the Macintosh platform.
RAID 10
The Areca ARC-1221x supports RAID 10 with a special feature. An even number of hard drives is not required. This option allows the ARC-1221x to support a RAID 10 configuration with a hot spare while using only eight hard drives. This setup allows the user to configure a hot spare with a RAID 10 volume without reducing the RAID size to an even number of disks.
Areca ARC-1221x vs RocketRAID 2322 - RAID 10
| Area Full | write | read | write | read | write | read |
| empty | 302 | 294 | 267 | 257 | 269 | 295 |
| 10% | 305 | 293 | 267 | 256 | 281 | 296 |
| 20% | 298 | 286 | 262 | 250 | 279 | 291 |
| 30% | 289 | 281 | 255 | 243 | 283 | 282 |
| 40% | 279 | 270 | 246 | 234 | 272 | 272 |
| 50% | 265 | 258 | 232 | 224 | 258 | 258 |
| 60% | 250 | 242 | 218 | 211 | 241 | 244 |
| 70% | 233 | 227 | 204 | 195 | 228 | 228 |
| 80% | 212 | 205 | 186 | 178 | 198 | 210 |
| 90% | 186 | 181 | 164 | 156 | 182 | 185 |
| 100% | 154 | 151 | 136 | 131 | 151 | 155 |
| Average | 252 | 244 | 222 | 212 | 240 | 247 |
| Format Size | 1.16TB | 1.02TB | 1.16TB | |||
| Hot Spare | No | Yes | No | |||
| Redundancy | Yes | Yes | Yes |
In the table above, Disk Tester results are provided for an eight drive ARC-1221x RAID 10 with and without a hot spare. For comparison purposes the performance results of the HighPoint RocketRAID 2322 configured with a RAID 10 and the same drive setup are also included. The ARC-1221x controller was able to provide a 5% average write performance advantage.
DiscussionThe Areca ARC-1221x PCI-Express eight channel, dual Mini-SAS to SATA RAID controller ($799) provides an amazing number of features, high performance and ease of use. The EnhanceBox E8-ML 8-bay enclosure provides a great match for mounting hard drives with this high quality RAID 6 controller.
The Areca web interface is very responsive and provides a wide range of user options. The "Quick Create" menu allows users to easily configure a wide range of RAID types. RAID 0, RAID 10, RAID 10 + spare, RAID 3, RAID 5, RAID 6 and combinations with hot spares are all available from an easy to use selection menu.
If the user needs more options the "RaidSet Functions" menu allows them to create or delete a RAID set, expand the RAID set, create or delete a hot spare and rebuild or rescue a RAID set. In addition, a pass-through mode is available that allows a disk to be controlled by the computer OS instead of by the ARC-1221x.
The Areca web interface provides the ability to turn off the alarm, set background task priority, set up the card for RAID or JBOD, enable read ahead cache, set the time to stagger drive powering and spin down hard drives after they have been idle for a selectable amount of time.
The Areca ARC-1221x provides users with the ability to utilize existing SATA enclosures while enjoying the redundancy of RAID 6. Computer users should always have a backup of important data. The implementation of RAID 6 adds another layer of protection for data storage systems. This feature helps users to avoid resorting to backup copies when recovering from a hard disk failure.
The Areca ARC-1221x RAID 6 controller may seem expensive when compared to the RAID 5 capable HighPoint RocketRAID 2322. However, RAID 6 provides twice the redundancy of RAID 5 and the ARC-1221x can be configured to support Mac booting. The ARC-1221x is competitively priced in comparison with other eight channel RAID 6 controllers that utilize dual Mini-SAS connectors. Users that want to upgrade to RAID 6 while still using their existing SATA direct connect and multilane enclosures will find the Areca ARC-1221x provides a high performance option and an excellent value.
Pros
Macintosh boot capability available when ARC1221EFI BIOS is installed.
High Performance RAID 6 configuration is easy to use and setup.
Supports up to 8 hard drives on a single host adapter.
Provides RAID 0, 1, 3, 5, 6 and 10 configurations.
Can be used with direct connect SATA enclosures.
Can be used with Multilane Infiniband enclosures.
Web Interface allows the alarm to be disable