Author: William Henning
Editor: Howard Ha
Publish Date: Wednesday, May 3rd, 2006
Originally Published on Neoseeker (http://www.neoseeker.com)
Article Link: http://www.neoseeker.com/Articles/Hardware/Reviews/xms8500/
Copyright Neo Era Media, Inc. - please do not redistribute or use for commercial purposes.
Corsair has been producing high speed DDR2 modules for quite a while; and they recently shipped us their TWIN2X1024-8500 dual channel memory kit for review. The kit consists of a matched pair of CM2X512-8500 modules that are tested at 1066MHz with 5-5-5-15 2T timing at 2.2V to qualify for the PC2-8500 rating.
Now that AMD is about to release socket AM2 and its related DDR2 memory interface processors, we are finally seeing the beginning of the end for DDR. The future will belong to DDR2 and newer memory technologies.
The Corsair site tells us that these modules are:
The benchmark guide also suggested some other timings that the modules work at:
Now we will test to see if the modules perform as specified... and can we beat the specifications?
Benchmark Setup
Our benchmark system (and competitors) consisted of the following:
We used Sandra and RightMark for our memory benchmarks - both give useful results in measuring memory performance.
Benchmarks
We used four different programs to test the influence of the memory bandwidth on different programs.
The 840 and 560 results are not comparable here as the 560 used our older benchmark setup (6600GT with 66.93 drivers) whereas the 840 uses our newer setup (7800GTX with 81.97 drivers); however the effects of FSB and memory speed with the same processor are still evident.
Overclocking
In order to get a good idea of the performance differences between stock and tweaked memory and processor settings, we are putting our test rig through quite a few tests!
Please note: in order to make our test results easy to read, we labeled the bars on the chart with the processor and memory settings - for example:
560 800 18x200
PC5400 800 4-4-4-7
Means 560 cpu, 800MHz CPU FSB, 18x200 processor setting,
PC5400 memory, 800MHz memory bus, 4-4-4-7 memory timing.
All memory timings at 2T.
Sandra Bandwidth
As you can see the overclocked Corsair XMS2-PC8500 memory got the second highest scores in Sandra here, with the top score going to the slightly underclocked PC8000 memory running with a slightly faster processor FSB and better timings.
The slightly underclocked PC6400 memory with better timings and faster FSB snuck into third place, then the next three spots were all PC8500 :-)
WinRAR
WinRAR is very sensitive to both processor and memory speeds; so we should not be surprised that the highest performance was obtained by a combination of high FSB and high processor speed. The PC8500 took the top three spots here!
RightMark Read
All I can say is WOW!
Just look at those RightMark Read Results... the PC8500 memory combined with the D 930 processor took the two top places on this chart, with excellent results.
Note that the top five spots were taken by the highest FSB speeds, so it would be fair to say that the memory throughput is limited by the FSB speed - something we've known for quite a while.
RightMark Write
The write rates we've achieved are nothing to sneeze at either, however lower latency memory combined with slightly faster FSB pushed the PC8500 memory out of the top two spots - but only slightly - and it took the next four spots.
RightMark Bandwidth
The pattern is obvious. Fast FSB and low latency wins for writes, and since writes make up a good portion of the RightMark bandwidth test, the PC8500 memory loses out to a high FSB PC8000 test with lower latency. Not that it loses by a significant margin, and it does take the next three spots. Again, excellent performance.
RightMark Latency
This is where we see the latency issues of DDR2. The lower latency PC5400 memory running at 3-2-2-7 timing and a fast FSB comes out with the lowest measured latencies - not a surprise. We can also see that DDR2 even with higher latencies can still turn in a decent performance overall (for latency) - as long as it can run at a high enough frequency. The PC8500 memory proves this by taking the next four top spots.
Doom 3
PLEASE NOTE: This test is NOT fair for the 560 based system or even some 840 results, as it used the older 6600GT and older drivers. You can see where we switched cards and drivers, results with less than 159 FPS were with the 6600GT.
Ok, the Corsair PC8500 took the two top spots. By a decent margin.
Damn these are VERY decent scores!
Conclusion
OK, let's first restate the obvious.
The charts clearly show that high FSB, combined with fast overclocked CPU's and fast memory dominates.
Well, duh.
What's not obvious from the charts is that the Corsair XMS2 PC2-8500 significantly outperformed its stated specifications.
I was able to complete these tests running the memory at 2.1V, 0.1V UNDER specification.
I was able to run the memory at a PC2-9120 rating - a VERY significant increase over the PC2-8500 rating it is assigned.
In modern Intel systems, the FSB presents a significant bottleneck to using the full memory bandwidth made available by high performance DDR2 modules. We are not going to see the full potential of even PC6400 memory until the FSB hits 1333MHz, and we'd need to hit 1600MHz FSB to fully be able to utilize PC8000 memory.
Nevertheless, the performance of the XMS2-8500 modules was excellent, it overclocks superbly, and I can't wait to try them on AMD's upcoming AM2 processors with integrated DDR2 controller.
Please do not redistribute or use this article in whole, or in part, for commercial purposes.