E8400 On showing as 2Ghz in CPUz

neilw · 2 Oct 2008 at 10:35

Why does my E8400 only show as 2ghz 333*6 in CPUZ. Also my Corsair Dominator Memory only shows as PC6400 not PC8500.

Motherboard is an Asus P5Q
Graphics card is a Asus 4850

3DMark06 score was 10600ish does this sound correct.

Thanks

Pneumonic · 2 Oct 2008 at 10:43

You have speedstep enabled which is running the CPU in powersaving when its idle hense the lower clock.. if you load the system you will see this jump back up...

I would imagine you are looking at SPD in CPUz which is giving you default values for the RAM... I shouldnt worry shows my OCZ as PC6400 not PC9600

neilw · 2 Oct 2008 at 11:52

Thanks, Do most people have Speedstep disabled then?

Pneumonic · 2 Oct 2008 at 13:10

depends on the board.. Asus boards dont decrease vcore on the down step so it doesnt cause instabilities when the system is clocked.. other boards do and you might find it does therefore cause instability..

I clock with it on.. as your running a Asus P5Q I dont see it would do any harm keeping it on

MooMoo444 · 2 Oct 2008 at 13:11

Pneumonic said:
depends on the board.. Asus boards dont decrease vcore on the down step so it doesnt cause instabilities when the system is clocked.. other boards do and you might find it does therefore cause instability..

I clock with it on.. as your running a Asus P5Q I dont see it would do any harm keeping it on

Doesn't that defeat the whole point of speedstep if it still uses the same voltage while underclocked???

Pneumonic · 2 Oct 2008 at 13:13

I do believe its only when you are on manual clock settings.. (might be wrong there)

IF your using EPU engine then it does.. but you cant clock with that on

neilw · 2 Oct 2008 at 14:05

I see. So lets say I wanted a little overclock to say 3.2, I'd go for a fsb of 355 (I'm guessing the standard mulitiplier is x9), but the speedstep drops this to 6x, so at 355fsb the speedstep would step down to 355*6 2.13Ghz?

Is that correct?

Pneumonic · 2 Oct 2008 at 14:14

well 3.2 I would run @ 400 * 8

but yes you are correct

neilw · 2 Oct 2008 at 14:28

Whats the advantage of running x8 multiplier rather than a x9

Pneumonic · 2 Oct 2008 at 14:40

well technically higher FSB gives better performance (not real world noticable) but 400 * 8 is preferable to 355 * 9 as 400*8 will allow you to run PC6400 RAM in a 1:1 ratio at its rated frequency

Edit:

Although if you have a divider that will allow you to run the RAM @ 1066 = 355 * 3 then that is actually the better option for 1066 RAM (sorry thought you hade PC6400)

Indy500 · 2 Oct 2008 at 14:42

Most motherboards default to 800mhz memory speed with DDR2 1066 and above, you may have to set the speed manually in the bios.

neilw · 2 Oct 2008 at 14:44

Cool thanks for explaining.

Might have a play later. I'll goto 3.2 for now as I've only the stock cooler. Will the E8400 go to 3.6 with out getting into voltage changes ect

neilw · 3 Oct 2008 at 11:59

Hopefully some body can give me some pointers here. I tried to clock my system, but each time it failed too boot.

I entered a fsb speed of 355 to get 3.2mhz. And also manually set the multiplier to 9, disabling the speedstep.

This adjusted the Ram Speed automatically, So I selected a speed of the ram that was lower than the 1066mhz its rated at but still no joy. I'm probably missing something very simple here. Any ideas