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Fast and Secure: A Comparison of Eight RAID Controllers
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1. Expansion Cards Better Than Onboard Chips

PC users can more than double system performance by using a RAID system instead of a single hard disk. The fastest IDE RAID controllers in our test achieved an average data transfer rate of over 55 MBytes per second. The leader of the pack was the Highpoint Rocket Raid 404, with 56,800 kBytes per second in RAID-0 mode. Without RAID, the same test system managed only 24,250 kBytes per second.

More and more modern motherboards are being fitted with onboard RAID controllers. The Promise chip supplied with some boards is no more than a 'scaled-down' version. Unlike the full PCI card version, it provides no support for combined RAID level 0 and 1 or a JBOD setup (several different hard disk types configured as a single hard disk). Onboard solutions are also less flexible in the event of a problem. If you are using a PCI card RAID controller to mirror your files and your motherboard develops a fault, you can install the controller and hard disks in another PC and carry on working. If the RAID chip is integrated with your motherboard, however, you will need to find another identical board before you can access your data.

Wide Range Of Cards Under Test

We examined eight IDE RAID controllers in our labs. Five of these were fitted with two channels for connecting four hard disks. The four-channel controllers - 3Ware Escalade 7850, Highpoint Rocket Raid 404, and Megaraid i4 from LSI Logic - let you connect up to eight hard disks. The LSI card, the Adaptec ATA Raid 1200A, and the Dawicontrol DC-100 Raid are equipped with an Ultra-DMA/ 100 interface; the others provide support for Ultra-DMA/ 133. The controllers from Adaptec, Dawicontrol, Highpoint and Promise allow RAID configurations with levels 0, 1, 0+1 and JBOD (Just a Bunch of Disks). he least expensive product is our budget category winner, the DC-100 Raid. The RAID-5 controllers Escalade 7850 and Megaraid i4. These are the only two cards with an integrated cache.

2. Performance And Security

You will achieve a considerable boost in hard disk performance with a RAID-0 configuration. The speed increase is achieved by reading and writing on more than one hard disk at the same time. There is no redundancy, which means that you will lose your data if only one hard disk should fail. The risk of losing your data is even greater than in a normal hard disk setup. With RAID-0, there are at least two hard disks that could go wrong.

A RAID-1 system offers the PC user an increased level of security, because it protects against data loss in the event of a drive failure. If a failure occurs, the remaining drive carries on unimpaired.

RAID-5 arrays protect against data loss, as well as providing faster throughput. Your data is distributed across at least two hard disks, with error correction information stored on an additional disk.

If you require constant availability from your hard disk system, you should choose a hot-pluggable controller. By using optional hard disk caddies, faulty drives can simply be exchanged while the system continues to operate. All the products we tested provide this option.

Limited Scalability

As far as pure data transfer is concerned, modern IDE drives are no longer inferior to SCSI drives - and they are considerably cheaper. But SCSI technology is not yet obsolete. The choice of drive depends on the type of application. A SCSI configuration is a few percent faster overall - particularly in multi-user environments where fast access to a database is needed. The SCSI architecture has an advantage in instances when you expect to expand the system at a later date.

The scalability of an IDE RAID system is not in the same league. Cable lengths are limited to 43 centimeters, and only two IDE devices may be connected to any one channel. SCSI allows at least seven.

Twice The Performance For Not A Lot More

The main argument in favor of IDE RAID is its good price/ performance ratio. It allows you to achieve a substantial increase in PC system performance and data security for a reasonable cost. For example, a system with two 120 GByte hard disks (Maxtor 4G120J6) and our budget winner Dawicontrol DC-100 Raid would cost you just under $400.

3. Test Procedure And Evaluation

We carried out all the RAID controller tests on a system fitted with an Asus CUR-DLS motherboard, an Intel Pentium III/ 1000 processor, and 256 MB of RAM. For our reference hard disks, we chose two 160 GB Maxtor drives (4G160J6) and a 120 GB Maxtor 4G120J6. The operating system was Windows XP.

The overall scoring in this eight IDE RAID controller group test is derived from three standardized categories which we weighted differently. These categories are Performance, Features and Service.

Performance Is King

Performance accounts for 60 percent of the overall score. The performance measurements are divided into five individual disciplines, each with a different weighting. Each product was subjected to a benchmark test in a configuration consisting of two hard disks in RAID level 0 and 1. If supported by the controller, we also carried out measurements in a RAID-5 configuration using three drives.

We examined the Office and high-end performance of the RAID systems using Business Disk and High-end Disk Winmark 99. Both were weighted at 25 percent. We used Transfertool to measure the average data transfer rate of the complete system.

Content Creation Winstone 2001 runs scripts using real applications such as Internet browser, image, sound and video editing, Web design, and multimedia applications. Winstone 2001 took care of our Office performance measurements. This program runs Microsoft Office 2000, e-mail and antivirus programs, a project planner, Internet browser and compression tools. To gauge multitasking capabilities, both benchmark programs automatically switch back and forth between the standalone applications.

Upon completion of the benchmarking, the Business Winstone and Content Creation Winstone programs are automatically removed from the Windows registry, and the system environment is restored to its original state for the next test.

Help With Finding Drivers

Service accounts for 10 percent of our overall rating. Here we have included the length of the warranty and the quality of customer support via corporate website and hotline.

RAID controllers need the latest drivers to work effectively. Our lab engineers will tell you that operating system updates often cause compatibility problems with the operating system's default drivers. For this reason, it is extremely important that manufacturers support their customers by providing easy access to new drivers and firmware updates.

4. Know How: RAID Levels And Glossary

The level of a RAID system (Redundant Array of Inexpensive Disks) relates to its operating mode and how the hard disks are combined to form a single logical drive.

RAID- 0

RAID-0 is not really a RAID level as such, because there is no redundant drive. The data is distributed across the available disks using a process called striping (also called "stripeset"). This technique is used to build a common data area and to achieve higher speeds. The controller merges several hard disks into one large, logical drive. As the data is written and read in a quasi-parallel fashion, overall performance is boosted compared with just a single drive. This is of particular benefit for video editing and image editing programs. However, if one drive fails, you lose the data on all drives.

RAID-1

RAID-1 (mirroring) involves mirroring the complete contents of one hard disk onto another. From the security standpoint, this is ideal (although not cheap), as the redundancy uses 50 percent of your hard disk capacity. There is a marginal increase in performance. Write access is slightly slower, but the controller uses the fastest available disk for reading data.

RAID-3

RAID-3 requires at least three hard disks, one of which is used to store error-correction data. Should a disk fail, the missing data can be restored from the parity and error-detection information on the redundant disk using an allocation algorithm. As RAID-3 interleaves the data across the drives, read speed is good, but writing is slower.

RAID-5

RAID-5 writes the original data and the error-correction information across all available drives (at least three). Writing is thus spread across all the drives in a RAID-5 system, which means that both reading and writing operations may overlap. RAID-5 offers good price/ performance, as only the space equivalent to one disk is allocated to the redundant data.

RAID 0+1

RAID 0+1 is a combination of RAID level 0 and level 1. The disks are combined using the striping technique, and then mirrored. This only makes sense if speed is a priority, since two mirrored drives represent an expensive form of insurance.

5. E-IDE Interface

This is not as important in practice as when using only a single disk drive. When RAID controllers with several hard disks are used, the PCI bus becomes the bottleneck. The benefits of the faster 133 MHz bus are not achieved.

Cache

Cache controllers use integrated cache memory to retain the data that is being transferred. This speeds up the transfer of data whenever data already stored in the cache is requested for a second time. Standard DDR-RAM is used for cache memory.

Hot-Plugging

Hot-plugging means that hard drives may be swapped while the system is running. The computer does not have to be switched off. This does not work with RAID-0.

Test Results In Detail

Five of the eight RAID controllers tested have a very low feature count. There is also some room for improvement as far as service is concerned.

The Highpoint Rocket Raid 404 delivers the highest performance of all of the models tested. In RAID-5 mode, the Escalade 7850 from 3Ware proves that data security and high speed are not mutually exclusive.

3Ware Escalade 7850

A maximum of eight Ultra-DMA/ 133 hard disks may be connected to the eight channels of 3Ware's Escalade 7850. The cache controller supports level 5 in addition to the usual RAID modes. This makes the most effective use of disk space. The speed penalty is about 10 percent compared with RAID levels 0 and 1, although, in practice, this will hardly be noticeable. The RAID-0 and RAID-5 results are close together at 56,800 and 56,750 kBytes per second (RAID-0 compared to RAID-5).

3Ware's Escalade 7850 controller earns first place with its good performance and features, and receives the recommendation of the editorial team. However, he Escalade 7850 is the most expensive product of the group by a considerable margin.

6. Adaptec ATA Raid 1200A

Adaptec's ATA Raid 1200A was a convincing performer in the lab. The controller achieved a good balance of results both in striped and in mirroring modes. Alongside the Highpoint Rocket Raid 133, this controller was the second fastest in the test.

Its features leave something to be desired, however. The controller has two channels and also supports the 0+1 combination. It is hot-pluggable, but the card is not fitted with a flash-bios, a buffer memory, or an external interface. Compared with the service provided by the competition, Adaptec's service is only satisfactory. The warranty period is three years, but the manufacturer does not offer an exchange service. The ATA Raid 1200A achieved fifth place in the group. Its price is too high.

7. Dawicontrol DC-100 Raid

The DC-100 Raid from Dawicontrol offers high speed and a good service back-up. This controller is the most inexpensive product in the group, and it comes with a five-year warranty that includes an exchange service.

Dawicontrol was the only manufacturer to fit its card with an external interface. The card is based on the Highpoint HPT370 chip, and a flash-bios enables the user to keep the specification up to date. In view of the good results and the low price, the Dawicontrol DC-100 gets our budget recommendation.


Only Dawicontrol equips its IDE controller with an external interface.
8. Dawicontrol DC-133 Raid

The Dawicontrol DC-133 is based on the Sil 0680 Ultra-DMA/ 133 chip from Silicon Image. The card achieved good scores, particularly on the application-oriented Business Winstone 2001 benchmark test. Obvious weaknesses highlighted by the Business Disk Winmark 99 cost the product some points.

The manufacturer provides this card with a five-year warranty against faults. Like the DC-100, the DC-133 has support for RAID levels 0, 1, 0+1 and a JBOD configuration in which the drives can be operated individually. A good feature is that one of the two IDE channels can be used externally, enabling arrays of external IDE hard disks to be used.

Thanks to a price, the Dawicontrol DC-133 Raid is a good value, although the DC-100 from the same manufacturer is a better and cheaper alternative.

9. Highpoint Rocket Raid 133

The product name says it all: the Rocket Raid 133 from Highpoint is fitted with a fast Ultra-DMA/ 133 chip. The controller has two channels for connecting up to four hard disks. The card was one of the fastest RAID-0 and RAID-1 controllers in the test. There were no weaknesses in any of the benchmark disciplines.

Features and service were judged to be only adequate. The controller has a flash-bios, but no external interface.

If a user should experience problems with the Highpoint Rocket Raid 133, he or she can turn either to the English language website, or to an American telephone hotline. The two-year warranty is the shortest of any of the products in the group.

10. Highpoint Rocket Raid 404

The Highpoint Rocket Raid 404 was judged to be the fastest IDE RAID controller in the group test by a very close margin. The performance in striping mode is a particular strong point for this controller.

A total of eight drives can be connected to the four channels in RAID levels 0, 1, 0+1, and as a JBOD. The lack of buffer memory and external interface is disappointing. A warranty period of only two years does not gain this card many points; neither does the non-existent exchange service and the exclusively English-speaking telephone hotline and website.

The Ultra-DMA/ 133 controller is suitable for applications such as audio and video processing, which require a high level of performance and a lot of disk space. With a good overall performance, the Rocket Raid 404 takes third place.


RAID management software from Highpoint.
11. LSI Logic Megaraid I4

The Megaraid i4 from LSI Logic proved to be a good Ultra-DMA/ 100 controller. It is equipped with 16 MB of cache and achieved good scores with RAID 0 and 1. In the RAID-5 comparison, however, it was behind the Escalade 7850 in every discipline.

At 16 MB, this card has the largest memory capacity of all the cards we tested. It supports RAID levels 0, 1, 3 and 5, plus the combinations 0+1, 0+3 and 0+5. The four-channel controller is based on the Sil 0649 chip from Silicone Image, is hot-pluggable, and allows connection of up to eight hard disks. With its five-year manufacturer's warranty, the Megaraid i4 gets good marks for service. Although not one of the top performers, the LSI card is a suitable alternative to the Escalade 7850.


The four channels of the LSI Logic Megaraid i4 are neatly arranged in line, and will accept up to eight drives.
12. Promise Fast Trak TX2000

The two-channel Promise TX2000 controller is based on the company's own PDC20271 chip, which supports Ultra-DMA/ 133. It did well in the Content Creation Winstone 2001 and Business Winstone 2001 benchmark tests, both in RAID 0 and in RAID 1 modes. The controller was not so fast on the Business Disk Winmark 99.

The TX2000 gets no points for features, as these were purely standard, but at least the controller allows hot-plugging of a new replacement disk drive. The warranty period is two years. The price is too high for the TX2000.

13. Scores And Features Table
Manufacturer 3Ware Adaptec Dawicontrol Dawicontrol
Model Escalade 7850 ATA Raid 1200A DC-100 Raid DC-133 Raid
Total judgement [Points] well 89 satisfying 77 well 80 satisfying 77
Performance (60 %) [Points] 90 94 93 88
Configuration (30 %) [Points] 92 47 52 52
Service (10 %) [Points] 70 64 90 90
Internet www.3ware.de www.adaptec.com www.dawicontrol.com www.dawicontrol.com
Price $499/€580 $120/€140 $55/€63 $69/€79
Technical data
E-IDE-Interface U-DMA/133 U-DMA/100 U-DMA/100 U-DMA/133
# channels 8 2 2 2
Max. hard disks 8 4 4 4
Cache Maximum/installed 2/2 MByte no/no no/no no/no
Raid levels supported 0, 1, 5, 10, JBOD 0, 1, 0+1, JBOD 0, 1, 0+1, JBOD 0, 1, 0+1, JBOD
Controller chip 3Ware Highpoint HPT370A Highpoint HPT370 Silicon Image SiI 0680
Configuration
External Interfaces no no yes yes
Flash-Bios yes no yes yes
Drivers
Windows 98/Me yes/yes yes/yes yes/yes yes/yes
Windows NT 4.0/2000/XP yes/yes/yes yes/yes/yes yes/yes/yes yes/yes/yes
Service and Support
Warranty 36 months 36 months 60 months 60 months
Additional Service replacement no replacement replacement
Manufacturer Highpoint Highpoint LSI Logic Promise
Model Rocket Raid 133 Rocket Raid 404 Megaraid i4 Fast Trak TX2000
Total judgement [Points] satisfying 76 well 82 well 85 satisfying 76
Performance (60 %) [Points] 94 94 87 88
Configuration (30 %) [Points] 50 70 81 55
Service (10 %) [Points] 46 46 84 69
Internet www.highpoint-tech.com www.highpoint-tech.com www.lsilogic.com www.eventus.de
Price $85/€100 $120/€145 $290/€350 $110/€135
Technical data
EIDE interface U-DMA/133 U-DMA/133 U-DMA/100 U-DMA/133
# channels 2 4 4 2
Max. hard disks 4 8 8 4
Cache maximum/installed no/no no/no 16/16 MByte no/no
Raid-Level supported 0, 1, 0+1, JBOD 0, 1, 0+1, JBOD 0, 1, 3, 5, 10, 30, 50 0, 1, 0+1, JBOD
Controller chip Highpoint HPT372A Highpoint HPT374 Silicon Image Sil 0649 Promise PDC20271
Configuration
External Interfaces no no no no
Flash-Bios yes yes yes yes
Drivers
Windows 98/Me yes/yes yes/yes yes/yes yes/yes
Windows NT 4.0/2000/XP yes/yes/yes yes/yes/yes yes/yes/yes yes/yes/yes
Service and Support
Warranty 24 months 24 months 60 months 24 months
additional services no no yes replacement
14. Recommendations
3Ware Escalade 7850

Based on the strength of its good performance and features, the "Editor's Choice" goes to the 3Ware Escalade 7850. It is even easy to use. The technical performance of this high-end card makes it particularly suited for use in entry-level servers.

Dawicontrol DC-100 Raid

The DC-100 delivered convincing benchmark scores and service support. With a five-year manufacturer's warranty including exchange service, the DC-100 is our "Budget Recommendation."