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Discussion Starter #1
Well I just did some benchmarks and discovered my brother's Kingston crap RAM runs faster at 900MHz 5-5-5-15 than 960MHz 5-5-5-15.

The values I found were:
900MHz 5-5-5-15 1.9V
read: 7009MB/s write: 6341MB/s copy: 6760MB/s latency: 71.3ns
960MHz 5-5-5-15 1.94V
read: 6773MB/s write: 6336MB/s copy: 6719MB/s latency: 77.9ns

This was using Everest benchmark. Am I right about the FSB straps or is this something else?
 

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Your mobo is the Asus Rampage Formula X48?

Then, unlikely.

Way more info needed.

CPU info (multi x FSB was what?)

RAM ratios for the above.

Subtimings info (tRD was @ what?).
 

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Discussion Starter #4
12.5x multiplier, 300MHz FSB
Ram ratios were 16:8 for 900MHz and 16:10 for 960MHz.
All timings were the same, although I gave the RAM an extra 0.04V in between those settings.
 

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Quote:

Originally Posted by nolonger View Post
12.5x multiplier, 300MHz FSB
Ram ratios were 16:8 for 900MHz and 16:10 for 960MHz.
All timings were the same, although I gave the RAM an extra 0.04V in between those settings.
Wat?

If FSB is 300 + DDR2-900, that's 2:3 ratio, which is on the 266 strap by default.
If FSB is 300 + DDR2-960, that's 5:8, which is 333 strap by default.

Anyway, 266 will apply a tighter tRD (& possibly other subtimings) if it's left on auto, which is precisely why you are getting better scores @ DDR2-900.

You can see tRD (Performance Level) with MemSet.

If you set tRD manually to the same, DDR2-960 will be faster.
 

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Discussion Starter #6
I'm sorry, I meant 2:3, not 16:8. Can't give that a try at the moment since the ram sticks are on my brother's computer, but I'll try tomorrow.
Thanks for the response!
 

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Iconoclast
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FSB straps often set the default tRD. Slower tRD at the faster strap is what's causing the performance discrepancy.
 

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OP, does the mobo offer a selection of the same mem multiplier but using different straps? For example, on my mobo bios, I have a 4.0, 4.0+, and 4.0~ settings--each denominator corresponds to a different strap--800, 1033, and 1333, IIRC. Is there an option for that in your bios? That might be a better indicator of strap effects.

Also, for your RAM, were ALL of the RAM timings/latencies manually set? Sometimes they are hidden in the main memory timing/latencies menu, and some are set to auto, which might also be the cause of the discrepancy.
 

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Old school
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Quote:

Originally Posted by nolonger View Post
I had some timings on Auto. For the FSB straps my motherboard sets them automatically based on what ratio I use.
But you can also set the straps manually, and then select a speed.
 
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