Question about memory timings and speed

Hulk

Diamond Member
Oct 9, 1999
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I realize that most memory modules are rated for a certain speed and timings. For example these are rated 1833MHz at 9-10-9-28, 1.5 Volts.

Is there a way to ascertain at say 1600MHz this memory (or any other) would run at lower speeds, say 1600MHz, other than trial and error testing?

Or is there a "rule of thumb" to approximate such things?
 

Blain

Lifer
Oct 9, 1999
23,643
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Memory will always run at a slower speed, but not necessarily at a lower voltage rating.
Some higher speed rated DIMMs are also rated at a higher voltage, say 1.65v.
Running these DIMMs at a lower speed doesn't mean they will function properly at a voltage less than what they are rated at.

If you want to run memory at the rated voltage but a lower speed... You're golden.
 

KingFatty

Diamond Member
Dec 29, 2010
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The memory may have operational information showing what the ratings are, perhaps they mention some lower voltage possibilities when run at slower speeds.
 

Hulk

Diamond Member
Oct 9, 1999
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I didn't ask my question correctly. Besides trial and error testing is there any "rule of thumb" on what timings you can run a certain stick if you are running it slower than rated. For example, the stick mentioned above is rates at 1833, timings 9-10-9-28. If run at 1600MHz, how much do you think the timings could be lowered? Do you think it would run CAS 8 instead of 9?
 

=Wendy=

Senior member
Nov 7, 2009
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www.myce.com
The utility CPUZ (SPD tab) will generally list the JEDEC info including timings, and voltage, for running memory at lower speeds.
 

KingFatty

Diamond Member
Dec 29, 2010
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Yes look at that SPD info, you can select multiple listings to see the various different settings.
 

BonzaiDuck

Lifer
Jun 30, 2004
16,709
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Yes look at that SPD info, you can select multiple listings to see the various different settings.

Certainly the best approach would be checking the SPD information.

I also compare kits rated at different speeds and same or different voltages from the same manufacturer. For instance, if one kit of G.SKILL is spec'd at 1600 and 9-9-9-24, and a second kit is rated at 1866 10-10-10-28, you can also compare the voltages, and it would be quite likely that the RAM at 1866 spec will run at precisely the specs of the 1600 RAM.