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DDR-I versus DDR-II
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Posted on: Apr 01, 2005 |
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We are often asked about the differences in performance between DDR2 and DDR1. This article should provide you with the appropriate information. Our testing was done on Intel’s LGA775 platform.
Overall, we can say that DDR400 appeared slightly more powerful than DDR2-533, although the difference is not enormous. In this article, we have investigated this further and have also compared DDR500 with DDR2-667.
Test Protocol
No motherboard allows DDR2-667 or DDR500 to function with a 200 MHz FSB.
This being the case for any FSB frequency, the RAM/FSB ratio remains at 1:1.
For a DDR1 vs DDR2 comparison, we used the following configurations:
* Pentium 4 'EE' 3.0 GHz - 15*200 - i875P - Dual DDR 400 - CAS 2
* Pentium 4 'EE' 3.0 GHz - 12*250 - i875P - Dual DDR 500 - CAS 2.5
* Pentium 4 'EE' 3.0 GHz - 15*200 - i925X - Dual DDR-II 533 - CAS 3
* Pentium 4 'EE' 3.0 GHz - 12*250 - i925X - Dual DDR-II 667 - CAS 4
We chose timings in DDR400 and DDR2-533 modes, CL2 and CL3 which are the lowest for the two platforms. Then, we moved the FSB to 250 MHz to obtain memory frequencies to match with those of DDR500 and DDR2-667.
The DDR1-500 easily exceeds the results of DDR2-533, but the top product is DDR2-667. With tight timings, DDR2-533 has the advantage over DDR1-400, whereas with looser timings, DDR1-400 takes the advantage.
It seems clear that DDR2 benefits more from a high FSB than does DDR1. The more the memory frequency increases and the more the FSB goes up the greater the performance , with a progression that is not linear. The concluson is that the throughput obtained makes it possible to compensate for higher and higher memory timings.
DDR1 offers a better response time. The bandwidth obtained by DDR1-500 isn’t able to compensate for the higher timings, whereas DDR2 can since the asynchronous mode in 4-4-4-12 offers a lower latency than DDR2-533 and 800FSB at 3-3-3-5.
This testing shows that he gain by going from DDR2-533 to DDR2-667 is greater than the gain from DDR1-500 to DDR1-400.
It can be seen again the much greater increase in the DDR2-667 mode over DDR2-533, especially compared to DDR1-500 vs DDR1-400 .
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