ram and cpu at different speeds

Titanion

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I am wanting someone to talk me into slowing down my ram... I am running a Soyo KT333 Dragon Ultra Black with my Barton 2500+ at 16.5x134 and Corsair PC2700 at 167. Last spring I tested 3DMark2001SE with my ram at 133 and then at 166, with my cpu at 133 both times, and I got higher marks with my ram at 166... but I keep reading again and again that my system will perform better with my ram slowed down...

Is there a better way to test performance both ways?

What is the science involved here?

<font color=red><b>To reign is worth ambition though in Hell:
Better to reign in Hell, than serve in Heav'n.</b></font color=red>
John Milton, <i>Paradise Lost</i>, II 262-263
 

Crashman

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Sometimes you'll see increased peformance due to decreased latency (for Cas2 as an example, 2 166MHz cycles happen faster than 2 133MHz cycles). The optimal solution is to reduce the latency setting and run it synchronously.

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Titanion

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Your post seemed to read as a kind of contradiction... I am still a little confused about your advice. If you would indulge me one more time, I would appreciate it.

Thanks.

<font color=red><b>To reign is worth ambition though in Hell:
Better to reign in Hell, than serve in Heav'n.</b></font color=red>
John Milton, <i>Paradise Lost</i>, II 262-263
 

addiarmadar

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If you have the clock of the ram identical to the CPU clock, that would be one less conversion the mobo has to do, thus inceasing performance. Also another pointer, upping the cpu clock is WAY better than upping the multiplier. Just put it at 167 and adujust the multiplier. Should run faster and more stable.

Barton 2500+ @ 2200mhz (10x220 vcore @ 1.8)
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Titanion

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I have no 1/5 divider on my board, or ya, I would push up the bus speed... my modem actually crashed one time when my bus was at 135 while I was playing Diablo2 with a friend online... it kept crashing until I figured out what the problem was...

Well, from the standpoint of the motherboard doing less work, the performance should increase, but what if my scores remain higher in 3DMark2001SE, 3DMark2003, and Aquamark with mr ram at 167? Should I then leave the two speeds at different rates, or are the higher scores meaningless? I have only tested 3DMark2001SE with both cpu and ram at 134, but not he others... and I scored higher with my ram at 167.

I will run those tests this weekend and post results...

<font color=red><b>To reign is worth ambition though in Hell:
Better to reign in Hell, than serve in Heav'n.</b></font color=red>
John Milton, <i>Paradise Lost</i>, II 262-263
 

Crashman

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Former Staff
OK, there are different things to consider:
1.) AMD processors can't make good use of additional memory bandwidth because the CPU bus is DDR as well.
2.) Normally running synchronously means the memory controller has less work to do and can run more efficiently.
3.) Sometimes #2 isn't completely true simply becuase of cas latency. If your memory was set at 2 cycles of latency (Cas2), it would take it 12ns to respond at 166MHz (DDR333), but 15ns to respond at 133MHz (DDR266). Do the math, it takes 6ns for 1 clock cycle at 166MHz, 7.5ns for one clock cycle at 133MHz.

One other thing: Synthetic benchmarks can often show advantages that real programs can't reproduce.

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<font color=red>Only a place as big as the internet could be home to an ego as large as Crashman's!</font color=red>
 

Titanion

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Crashman... you are all over this forum helping everyone out... you are awesome... there are a lot of other helpful people, too, but you stand out...

I do have some good Corsair Cas2 ram...

<font color=red><b>To reign is worth ambition though in Hell:
Better to reign in Hell, than serve in Heav'n.</b></font color=red>
John Milton, <i>Paradise Lost</i>, II 262-263
 

Titanion

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This is a bump for a post called 5:4 stinks or something like that...

<font color=red><b>NF7-S/Mobile Barton 2600+
210x12.5 1.808v SLK900A
1GB Corsair XMS PC3200
Sapphire 9500np@9700np</font color=red><font color=black>
NF7-S/Barton 2500+
200x11.5 1.76v
512MB XMS PC2700
XFX Ti4200