5600 2.9

mollymoo · 19 Apr 2009 at 20:32

Am I right in thinking that to find the memory frequency on a cpu @ 2.9 @ 14.5 multi it would be 2900 / 8 = 362.5?
If I buy this processor and oc it to 3200 @ 14.5 it should give me 400 or wouldn't it?
And if I can't oc to 3200 can I just drop the multi to 14 and then achieve 400?
Tried oc on my 4600 and it appeared my ram didn't really like it so I'm trying to do it without going over on the ram.

mame · 19 Apr 2009 at 22:36

At around that speed using a 14.5 divider you would probably use the 1:2 RAM divider meaning that your memory speed was 2x that of you FSB. So 200 fsb x14.5 = 2900mhz then RAM 1:2 would be 400mhz RAM speed. Even at 3200mhz, your RAM would only be about 441 which will 95% be OK.

If you want to find your max CPU speed then set the RAM at 1:1 which will put your RAM limit way way out of the equation. Once you find this you can then decide what the best RAM divider would be. You may well find that you get a better end result my raising your FSB and lowering your multi to give you the RAM speed that you want. The only slight down-side to this is that windows and a lot of apps will report your clock speed wrong. If you set 300*10 (3GHz) windows will show that you have 4350MHz.

A more direct answer to your question is no, with a 14.5 multi, you will not be held back by your RAM. In theory you could go all the way up to 5.8ghz using the 14.5 multi and a 1:1 divider and still only have your RAM running at it's rated 400mhz. Even then you could probably go futher!!

mollymoo · 20 Apr 2009 at 08:52

Now i'm confused I cant see how running said processor @ 5.8ghz @ 14.5 multi using a 1:1 divider can possibly leave my ram running @ 400mhz ........... I thought it would run at 725 ....... I must be missing something.

mame · 20 Apr 2009 at 11:21

The final CPU clockspeed and the multi dont have an effect on the RAM speed. The RAM speed is determined by your FSB and RAM multiplier.

So if you had 200 FSB x 14.5 (2.9GHz) and a memory divider of 1:2 then your memory would be x2 that of you FSB so in this case 400 MHz.
If you dropped the CPU multi to 10 (2.0GHZ) the RAM would still be exactly the same, 400MHZ.
If you then changed the RAM divider to 1:1 the RAM speed would be 200MHZ as it would match your FSB.
If you then put your CPU multi back to 14.5 (2.9GHz) your RAM would still be 200 MHz.
If you then upped you FSB (remember your RAM is matching this 1:1) all the way to 400 then the CPU would be at 5.8GHZ (400 x 14.5) and the RAM would be at 400mhz.

Obviously the CPU won't get that far but it shows how your RAM will never be able to hold it back because the 14.5 multi allows you to use a much lower FSB. When someone says they are held back by their RAM it's because you can't divide memory lower than 1:1 so if your FSB was 500, your RAM would HAVE to be able to run at 500MHz or you won't be able to run your CPU at that speed. So if someone had:

a Q9300 with a 7.5 multiplier which was capable of 3750 MHz
A motherboard that could run at 500 FSB
They would run 500 x 7.5 = 3750 BUT if their RAM could only run at 450 MHZ then they would be RAM limited to running at 3375 MHz

mollymoo · 20 Apr 2009 at 12:37

Thanks for your advice although it does seem to contradict any other advice except for one person who gave the same advice and then was told they were wrong as this is not the case for k8 processors....... apparently.
After googling it appears that this particular version of the 5600 runs @ 200x14.5 and this does affect the ram speed bringing it down to an odd size........ just need to decide what the right and wrong advice is or ............. wait till tomorrow when it turns up and see for myself.
Once again thanks for your time in this matter