RAM timing: Gigabyte GA-G33M-DS2R with Corsair CM2X2048-6400C4DHX

[Syncopated]

I'm using 2X2GB of 400MHz (PC2-6400) Corsair RAM (CM2X2048-6400C4DHX) with a Gigabyte GA-G33M-DS2R motherboard.

The CM2X2048-6400C4DHX is supposed to be 4-4-4-12 at 400MHz, according to NewEgg.com and to the EPP#1 column in the SPD tab in CPU-Z. However, the Memory tab in CPU-Z reports that the RAM is running at 400MHz, 5-5-5-18.

Does this mean that the RAM is running at a slower timing than it can? What causes a motherboard to use something other than the SPD settings when the user didn't give any tweaked BIOS settings? All my settings are at auto/default. Also, I don't see anywhere in the BIOS for tweaking the RAM timing. Does this motherboard allow RAM timing tweaking? If so, how do I do it?

 

[ghmage]

Control-F1 in the main screen of the GB bios to enable the 'hidden' settings under the M.I.T. Look at the SPD tab in cpu-z and see the differing default timings based on the bus speed. 4-4-4-12 is probably the default timings at 266, and 5-5-5-18 is probably the default timings at 400. So, bios reads the SPD and sets the timings to 5-5-5-18 for 400MHz. You can tweak it, of course - I do. I have my memory running at 4-4-4-10 at 333 - because it wants to do 5-5-5-12 for 400 by default.

 

[XMSYellowbeard]

The memory boots at SPD settings because it has to the first time it boots for compatibility to JEDEC specifications. If you leave it at all DEFAULT/AUTO then the memory simply runs at SPD settings. As noted, you will need to manually enter the BIOS and set the timings AND voltage manually.