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RAID Performance
RAID 0 (striping) offers double or more performance under sustained
data transfers. The idea behind this is to merge the capacity
of at least 2 HDD and to increase performance by distributing
data over all drives, so that they can be read in parallel. RAID
1 (known as "mirroring") creates an identical image
of data from one drive to a second drive or from multiple drives
to a second set of multiple drives. Should one drive fail, the
working drive set continues to operate. In order to utilize these
features at least 2 (ideally identical) HDD are necessary. Using
4 HDD (2 x master & slave) gives the best performance in RAID
0 or allows the combination of RAID 0 + 1. The latter combines
speedier data transfer with the safety of a mirrored drive. A
detailed explanation of RAID and its benefits can be found here.
For somebody not familiar with RAID it takes naturally some time to understand how to set up a RAID array. The HPT 372 set-up utility has to be accessed during the booting process after the RAID controller has scanned the system for existing arrays. For a more experienced person it's matter of a less than 5 minutes to select the drives to be arranged into an array, to choose the RAID mode, and to set the stripe size. The HPT 370/372 setup utility is easy to handle and works well. In order to check to the full functionality of the HPT 372 controller and to evaluate RAID 0 performance we arranged 4 identical Western Digital 40GB ATA 100 HDD as a RAID 0 array with a stripe size of 16 K. Of course, in order to evaluate the full performance of the new HPT RAID controller 4 ATA 133 HDD would have been better. But unfortunately that was beyond our budget.
A single ATA 100 HDD with 7,200 rpm provides typically a data transfer of around 25,000 ~ 30,000 KB per second, RAID 0 with 2 HDD provides for around 40,000~45,000 MB per second, and here we have what the HPT 732 RAID controller is providing in Raid 0 with 4 HDD as measured with the ATTO HDD benchmarking utility:
In theory any access to the HDD, be it loading of programs or saving of data, is accelerated with RAID 0. It's however an illusion to believe that RAID 0 offers any advantage for the usual desktop task, like surfing the web, writing documents with MS Office, or playing 3D games. As long as there are no huge files to work with, there is nothing to show off for RAID 0. Applications, which require a lot of reading and writing to the hard disk, instead of doing a lot of processing, benefit most from RAID 0. We benchmarked the KR7A HPT 372 controller with Ziff Davis Winbench 99 (version 2.0) using the Business Disk Mark99 and the High-End Disk Mark99 .The second one is based on several editing applications with intensive data transfers like Photoshop and Adobe Premier. It shows that the KR7A onboard RAID controller in RAID 0 with 4 HDD can provide a 20% better performance in data transfer intensive applications than a single IDE HDD. It also shows that in "regular" business applications the difference between a single IDE HDD and RAID 0 is negligible.
Overclocking the
KR7A
As already mentioned the KR7A comes with the full array of overclocker's
instruments of torture: adjustable CPU ratio, FSB settings in
1 MHz increments up to 200MHz, voltage settings for CPU, DIMM,
I/O. Unfortunately the KR7 offers only the usual 0.1 volt on top
of the default Vcore voltage. On the other hand, all adjustments
are possible in the BIOS, which makes things easy. The 7VTX-H
for example has only a dipswitch to set the CPU ratio; offers
no 4-bank interleave setting to improve bandwidth and less voltage
settings. The 8KHA+ is almost as complete as the KR7A with the
exception of the I/O voltage. Very useful for tweaking and overclocking
is that the KR7A offers a wide range of BIOS settings in particular
in the memory section. The KR7A has 3 predefined performance settings
from "Normal" to "Ultra".
In the overclocking department the KR7A really started to shine and clearly outperformed the contenders. The 7VTX-H and the 8KHA+ gave both up at 10 x 157 MHz. The KR7A made it to 10 x 161 MHz. We tried various other CPU ratio/FSB combinations, but the 7VTX-H and the 8KHA+ were always at the end at around 157 MHz. The maximum FSB frequency we achieved with the KR7A was 9 x 179 MHz. Probably helpful for overclocking is the high voltage we observed at the KR7A's 5-volt rail. We got a reading of 5.10 volt. The 8KHA+ dropped as low as 4.6 volt, when the core voltage was increased to the maximum of 1.85 volt. This is a widely reported issue of EPoX boards with the Enermax PSU. The 7VTX-H was constantly hovering around 4.95 volt.
What we cannot show in forms of scores and pictures is the fact that the KR7 remained very stable through all our overclocking attempts. Almost every board is "stable" when running at stock specifications. The differences show when a motherboard is approaching the limit. We can attest that the KR7A kept its course firmly until the end. After passing the maximum, the KR7A simply reboots. When too extreme values for the CPU ratio or FSB have been set in the BIOS, the KR7A normally falls back to the BIOS defaults. This is convenient because it saves the time to clear the CMOS. Only a very few times it became necessary to clear the CMOS to regain access to the BIOS. We did not get any BIOS check-sum errors with the KR7A.The 3-way power supply with 6 MOSFETS feeding the CPU certainly contributes to the KR7A’s excellent stability during our overclocking attempts. Some more information about the relevance of the CPU power supply can be found here.
Summary and Conclusion
The KT266A chipset is flying, and in the incarnation of the ABIT
KR7A it's flying very high. The KR7A-RAID is feature-rich, outperforms
the KT266A competition, and has huge overclocking potential. We
regard the KR7A as the current top choice among KT266A boards.
The KR7A-R carries a street price of around 150 USD in Asia. This
is 25% more than the 8KHA+ or 7VTX-H and makes the KR7A-R certainly
not a cheap motherboard. But to my mind it's still a fair price
considering the quality, performance and additional equipment
the KR7A boasts.
What we liked:
What we missed or did not like:
 DIY Parallel-Cable Remote LCD! |
 TwinMOS PC2700 DDR |
 MSI K7N420 Pro nForce Motherboard! |