As many of you will know, the memory setting in the bios tRD has the biggest single affect on memory performance.
Using MemSet from Tweakers.fr for "on the fly" memory tweaking and say Everest for memory benchmarking you can see the differences yourself as explained in the Anandtech articles below:-
AnandTech: ASUS ROG Rampage Formula: Why we were wrong about the Intel X48
AnandTech: ASUS ROG Rampage Formula: Why we were wrong about the Intel X48
However, during my recent tweaking I believe I may have found a bug in my bios (see sig) that may be present on other Gigabyte boards/bios version combinations.
Normally this wouldn't be a big deal, but as it does have a significant performance hit on memory throughput (by setting the bios incorrectly), I thought i'd share it.
Scenarios and the relavent settings that highlight the problem:-
(Cpu Host frequency 333Mhz)
Setup a
MIT Section-------------------------------->Windows MemSet 3.5
System Memory Multiplier = Auto
(800Mhz)
tRD (7) Auto-------------------------------->tRD = 7
Setup b
MIT Section-------------------------------->Windows MemSet 3.5
System Memory Multiplier = 2.40
(800Mhz)
tRD (7) Auto-------------------------------->tRD = 9
Setup c
MIT Section-------------------------------->Windows MemSet 3.5
System Memory Multiplier = 2.40
(800Mhz)
tRD (7) 7*---------------------------------->tRD = 7
*manually set to the same value as Auto
1) So basically with the settings in question set to Auto, there isn't a problem. The bios shows the tRD value of 7 and so does MemSet in Windows - hoorah!
2) However if you decide to set the System Memory Multiplier manually, ie in my case to 2.40 (333 x 2.40 = 800), without altering the tRD value from it's Auto Value (which is displayed in the bios correctly) - something causes that value (tRD) to change as you proceed into windows! Which is confirmed by Memset (and benchmarking to rule out a Memset reporting error).
3) But if you Set tRD in the bios to the value of 7 Manually (as per the value Auto suggests) effectively "locking" it, Memset will report the same (ie 7) when in windows.
So for some reason, if you choose to set The System Memory Multiplier Manually, but leave as per you might/would normally do with other memory bios settings to Auto - it might (as with my setup) be changing settings that you might not neccessarily think were connected to it.
There is a reasonable Memory performance hit by tRD being raised from 7 to 9, so I think this is worth noting.
See Benchmark:-
AnandTech: ASUS ROG Rampage Formula: Why we were wrong about the Intel X48
Using MemSet from Tweakers.fr for "on the fly" memory tweaking and say Everest for memory benchmarking you can see the differences yourself as explained in the Anandtech articles below:-
AnandTech: ASUS ROG Rampage Formula: Why we were wrong about the Intel X48
AnandTech: ASUS ROG Rampage Formula: Why we were wrong about the Intel X48
However, during my recent tweaking I believe I may have found a bug in my bios (see sig) that may be present on other Gigabyte boards/bios version combinations.
Normally this wouldn't be a big deal, but as it does have a significant performance hit on memory throughput (by setting the bios incorrectly), I thought i'd share it.
Scenarios and the relavent settings that highlight the problem:-
(Cpu Host frequency 333Mhz)
Setup a
MIT Section-------------------------------->Windows MemSet 3.5
System Memory Multiplier = Auto
(800Mhz)
tRD (7) Auto-------------------------------->tRD = 7
Setup b
MIT Section-------------------------------->Windows MemSet 3.5
System Memory Multiplier = 2.40
(800Mhz)
tRD (7) Auto-------------------------------->tRD = 9
Setup c
MIT Section-------------------------------->Windows MemSet 3.5
System Memory Multiplier = 2.40
(800Mhz)
tRD (7) 7*---------------------------------->tRD = 7
*manually set to the same value as Auto
1) So basically with the settings in question set to Auto, there isn't a problem. The bios shows the tRD value of 7 and so does MemSet in Windows - hoorah!
2) However if you decide to set the System Memory Multiplier manually, ie in my case to 2.40 (333 x 2.40 = 800), without altering the tRD value from it's Auto Value (which is displayed in the bios correctly) - something causes that value (tRD) to change as you proceed into windows! Which is confirmed by Memset (and benchmarking to rule out a Memset reporting error).
3) But if you Set tRD in the bios to the value of 7 Manually (as per the value Auto suggests) effectively "locking" it, Memset will report the same (ie 7) when in windows.
So for some reason, if you choose to set The System Memory Multiplier Manually, but leave as per you might/would normally do with other memory bios settings to Auto - it might (as with my setup) be changing settings that you might not neccessarily think were connected to it.
There is a reasonable Memory performance hit by tRD being raised from 7 to 9, so I think this is worth noting.
See Benchmark:-
AnandTech: ASUS ROG Rampage Formula: Why we were wrong about the Intel X48
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