ASRock 775Dual-VSTA: Does DDR2 matter?
by Gary Key on August 8, 2006 6:35 AM EST- Posted in
- Motherboards
Memory Performance
Our VIA based ASRock motherboard provides two DDR2 and three DDR memory ratios. The majority of end-users will select the memory ratio that matches their memory speed. We are testing four ratios at the fastest stable timings we can achieve and still pass our benchmark test suite. With these set ratios, CPU speed remains the same at 1.86GHz in our test platform with memory speed being varied by selecting the different ratios.
There are some downsides to this approach. With the memory controller in the chipset, instead of part of the processor as in AMD Athlon 64 systems, there is a small performance penalty for speeds other than a 1:1 ratio (DDR2-533 in this case). However, the penalty is in reality very small, though the performance between various chipset designs can vary a great deal as we will see in a future article.
Due to performance reasons we did not test the DDR266 setting as we believe most people will not need this setting. Although the BIOS offers a 1T Command Rate, we never could get this setting absolutely stable without drastically raising the memory latency settings. We even tried our more expensive memory modules with the same results. Our memory settings were derived from extensive stress testing with a variety of applications. While certain settings that allowed lower latencies worked well with certain applications, the final settings we arrived at had to work with all applications.
The memory performance result at DDR2-533 (1:1 ratio) leads the other memory speeds in all cases. This particular setting delivered the best raw performance although we will see in our application and game benchmarks that this advantage is negated by other platform components.
Normally memory bandwidth improves with increases in memory speed and reductions in memory timings. To evaluate memory bandwidth SiSoft Sandra 2007 Professional was used to provide a closer look at scaling. As we have been saying for years, however, the Buffered benchmark usually does not correlate well with real performance in applications on the same computer. For that reason, our memory bandwidth tests have always included an UnBuffered Sandra memory score. The UnBuffered result turns off the buffering schemes, and we have found the results correlate better with real-world performance.
In this case, we find the combination of our memory settings at DDR2-667 and the VIA memory controller generates Sandra results that are up 32% lower than the DDR2-533 settings. The DDR2-533 results are up to 48% better than the DDR-333 scores with the DDR2-667 and DDR-400 scores being comparable. The Sandra memory score is really made up of both read and write operations. It is also a synthetic benchmark that does not always reflect real world performance.
To provide more detail on the impact of memory performance, we also compared pure number crunching with Version 1.5 of Super Pi, using the time to calculate 2 million places of Pi at the different memory speeds. Our other memory test is the latency measurement from the latest version of Everest. The results are interesting as the DDR2-667 ties DDR2-533 in Super Pi while DDR-400 trails slightly and DDR-333 brings up the rear. Looking at the latency figures, DDR2-667 is almost equal to DDR2-533 and DDR-400 trails slightly, while the results for DDR-333 are terrible and follow the Sandra bandwidth figures when compared to our DDR2-533 scores.
Our VIA based ASRock motherboard provides two DDR2 and three DDR memory ratios. The majority of end-users will select the memory ratio that matches their memory speed. We are testing four ratios at the fastest stable timings we can achieve and still pass our benchmark test suite. With these set ratios, CPU speed remains the same at 1.86GHz in our test platform with memory speed being varied by selecting the different ratios.
There are some downsides to this approach. With the memory controller in the chipset, instead of part of the processor as in AMD Athlon 64 systems, there is a small performance penalty for speeds other than a 1:1 ratio (DDR2-533 in this case). However, the penalty is in reality very small, though the performance between various chipset designs can vary a great deal as we will see in a future article.
Due to performance reasons we did not test the DDR266 setting as we believe most people will not need this setting. Although the BIOS offers a 1T Command Rate, we never could get this setting absolutely stable without drastically raising the memory latency settings. We even tried our more expensive memory modules with the same results. Our memory settings were derived from extensive stress testing with a variety of applications. While certain settings that allowed lower latencies worked well with certain applications, the final settings we arrived at had to work with all applications.
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| Click to enlarge |
The memory performance result at DDR2-533 (1:1 ratio) leads the other memory speeds in all cases. This particular setting delivered the best raw performance although we will see in our application and game benchmarks that this advantage is negated by other platform components.
Normally memory bandwidth improves with increases in memory speed and reductions in memory timings. To evaluate memory bandwidth SiSoft Sandra 2007 Professional was used to provide a closer look at scaling. As we have been saying for years, however, the Buffered benchmark usually does not correlate well with real performance in applications on the same computer. For that reason, our memory bandwidth tests have always included an UnBuffered Sandra memory score. The UnBuffered result turns off the buffering schemes, and we have found the results correlate better with real-world performance.
In this case, we find the combination of our memory settings at DDR2-667 and the VIA memory controller generates Sandra results that are up 32% lower than the DDR2-533 settings. The DDR2-533 results are up to 48% better than the DDR-333 scores with the DDR2-667 and DDR-400 scores being comparable. The Sandra memory score is really made up of both read and write operations. It is also a synthetic benchmark that does not always reflect real world performance.
To provide more detail on the impact of memory performance, we also compared pure number crunching with Version 1.5 of Super Pi, using the time to calculate 2 million places of Pi at the different memory speeds. Our other memory test is the latency measurement from the latest version of Everest. The results are interesting as the DDR2-667 ties DDR2-533 in Super Pi while DDR-400 trails slightly and DDR-333 brings up the rear. Looking at the latency figures, DDR2-667 is almost equal to DDR2-533 and DDR-400 trails slightly, while the results for DDR-333 are terrible and follow the Sandra bandwidth figures when compared to our DDR2-533 scores.
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preacherman - Tuesday, August 8, 2006 - link
What would be intresting would be a maybe running at least the synth benchmarks on another C2D mobo.. with the same CPU,HDD;DDR2 etc etc.This would show us if the mobo as a whole runs at a performance handicap to others mobo or.. as I would hope.. basicly its up or near there in performance with most other C2D mobos with or without DDR2.
If that is the case then the mobo is truly very good for those of us not wanting to shell out 250e+ for 2x1Gb DDR2 when we already have 2x512Mb DDR sat in our current rigs so we could spend that money on CPU/GPU as you wrote in your atricle and maybe get DDR2 later as and when funds become available.
thanks.
Gary Key - Tuesday, August 8, 2006 - link
You will see this in the final comparison article. The general performance of the board is about the same as we reported in our Conroe Buying Guide. However, the 1.5 bios has improved performance in some areas.
yacoub - Tuesday, August 8, 2006 - link
I am surprised how little advantage DDR2 has over DDR memory. Very interesting. Was the difference greater from SDR to DDR? I forget.Locutus465 - Tuesday, August 8, 2006 - link
I'm guessing a higher end board with a better memory controller might show DD2 in a better light.retrospooty - Tuesday, August 8, 2006 - link
The same can be said for DDR.MY DFI Lanparty NF4 runs my Corsair BH-5 chips at 260mhz@ 2-2-2-7 timings. DDR2@ 1000mhz@5-5-5 cant even beat that.
Wesley Fink - Tuesday, August 8, 2006 - link
We did a top-end DDR vs DDR2 on the AM2 at http://www.anandtech.com/cpuchipsets/showdoc.aspx?...">http://www.anandtech.com/cpuchipsets/showdoc.aspx?.... Of course, DDR2 bandwidth on the AM2 is huge, even though it doesn't always translate into real-world performance gains. Conroe is not nearly as efficient as AM2 on memory but still outperforms by a wide margin. In the AM2 article we found fast DDR400 and DDR2-533 roughly equivalent, with faster DDR2 speeds providing a bit more performance.It appears with Conroe on a VIA chipset DDR2-533 gains more, but real-world is still in the ball park with DDR400. That may be a commentary on the VIA chipset and may not apply to Intel or nVidia or ATI. However, this VIA board is the first to allow a DDR/DDR2 comparison with Conroe.
There are other boards for Dore 2 Duo coming that will support DDR on Core 2 Duo. For the value builder, it will be interesting to see how this board compares to some of those.
JarredWalton - Tuesday, August 8, 2006 - link
In some instances DDR was quite a bit faster than SDR. I think it gave about a 10% performance boost on average, and up to 20% in a few special cases. It's also worth noting that the ASRock does offer lower performance than other high-end DDR2 boards, but the price tradeoff makes it justifiable.yyrkoon - Sunday, August 20, 2006 - link
Well, if you go by pure synthetic benchmarks, DDR is 5x faster than SDRAM most of the time. Actual application performance, may be different.Calin - Tuesday, August 8, 2006 - link
DDR was quite a bit faster than DDR - just the way it is now with DDR2 and SDR. However, in the budget side of the equation, the processors weren't starved enough for bandwidth, so the difference was very small.I wonder what the results would have been if a faster processor would have been used.
Oh, and maybe the chipset/BIOS isn't optimized for DDR2 performance (as for DDR, all the performance that could have been squeezed in about three-four years of building chipsets was already there).
Jedi2155 - Tuesday, August 8, 2006 - link
Did you mean DDR was quite a bit faster than SDR and now with DDR2 with DDR?