read speed quest

[Megatonone]

hope this is right forum group...

trying to understand diff in read speed on my setup and other similar setups but with diff mobo/chipset..

my specs are: asus a7v8x(kt400), xp2000, 1024mb pc2700 crucial (cl 2.5)not oc'd

when i run aida32 benchmark to look at my read speed i get around 1850mb/s. i understand because of my 133 MHz FSB that my scores will be close to PC2100 DDR scores as indicated by the 1850 reading but i'm trying to understand what causes higher read speed benchmarks with my abit kx7 kt333 mobo using same xp2000 and pc2700 cl2.5 (generic brand) ram (with this setup i consistently get 200mb/s higher read speed... i'm not concerned about this small diff... i would like to learn if this is due to the diff of the kt333 vs the kt400 or is it related to the diff mobo or some other variable...

i've tried other brand of pc2700 ram on my a7v8x setup and it makes no diff in readings (still around 1850)

also... since my fsb limits my to pc2100 readings... what's the advantage of running pc2700 on my asus board?

thanks for any help on understanding this....

mega

Megaton

 

[bum_jcrules]

There are two basic reasons that work together to cause what you are seeing.

First is the chipset itself. The second is the fact that the memory and the FSB have to use a intermediary signal to negotiate the frequency differences. If you had the FSB running at 166.667MHz and the memory at the same the ratio between the two frequencies is 1:1. When it is something other than 1:1 say 133.33MHz vs. 166.667MHz is 1 to 0.8. The MCH has to generate a signal that acts as a transmission between the two signals. This decreases the performance. Now this will happen on both the KT333 and the KT400 boards but the controller on the KT333 has been shown to have better yields than the KT400. THG has done articles on it before.

There are sub issues that can add to it.
PCB layout
PCB layering
Chipset
Memory PCB
Memory Chips
All of the Latency timings
Etc.

What do you have your PH Limit and Idle Timings set for? You could have this too low or too high. Make it 8 or 16 and you can see higher scores.

I don't know if this fully satisfies your question, but it is an attempt.

<A HREF="http://forumz.tomshardware.com/community/modules.php?name=Forums&file=viewtopic&p=28752#28752" target="_new">THGC meeting? Would you go if there was one?</A>

 

[Megatonone]

thanx bum... you've given me all i was wanting plus much more. i welcome all you've provided and now have a lot to study and learn to fully understand.

thanx, mega

Megaton