Everest bench: CL7 lower performance than CL8?

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magnu55

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Jul 25, 2010
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I'm benching using Lavalys Everest and with all settings the same except for memory timings, I get the following:

DDR3-1600 7-8-8-20-1T: read 17229 MB/s, latency 39.2 ns
DDR3-1600 8-8-8-20-1T: read 18517 MB/s, latency 46.3 ns

Does that look correct to you? CL7 has lower read bandwidth than CL8?! I always assumed the lower the CL the higher the performance, no?

Rig is i7-930 @ 4.2ghz (200x21)
 
The lower the CL, the lower the latency, not higher bandwidth. Your numbers show that it did help in that aspect. The bandwidth depends on the frequency of the memory.
 
hmm but both cases are clocked at 1600 so why is there the bandwidth difference? Also, I guess given these results, which case would you go for then? CL7 or CL8?
 
any more information please? Is latency inversely related to bandwidth? I can't find any relevant information from the web.
 
doesn't make much sense to me. did you try rerunning both tests (after a reboot)?
 
What about the sub-timings?

I am betting the motherboard automatically changed some of them when you changed to CL7 from CL8.

That right there can make that much of a difference.

Does your board list what the sub-timings are when set to AUTO? If so, change back to CL8, reboot, go back into the BIOS, set all of the sub-timings manually, and then change to CL7.
 
cyclone3d, i think you may be on to something here! I changed all the AUTO settings for memory in bios to whatever they were at 8-8-8-20-1T then I changed from CL8 to CL7 and guess what my read and latency times were the same as what I got for 8-8-8-20-1T -> that seems to imply going from CL8 to CL7 did not improve the benchmarks!

So, by going from AUTO to whatever the values were at CL8 must have prevented any improvement to latency from CL7. Problem is, I don't know what the settings are when I set to CL7 and leave the other settings to AUTO otherwise I can play around with them.

my next question is: is there any program that can show ALL the memory timings in windows?
 
CPU-Tweaker should be able to:

http://www.tweakers.fr/cputweaker.html

The timings in the program aren't always named the same exact thing in BIOS, but you should be able to play around with it and check what changes in the program when you change somthing in the BIOS.

Not sure about your system.. but you may be able to actually use it to change and test different timings in Windows.
 
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