PC6400, PC8500 or higher?

Guest2 · 15 Feb 2010 at 21:55

My board states this 'Support for DDR2 1333+/1066/800/667 MHz memory modules' What would be good overclocking memory for a Q6600? Is it better to have lower timings on 800mhz (pc6400) memory or slacker timings higher PC?

I see people recommending overclocking memory of PC6400 on some forums. Would something like this be better

http://www.overclockers.co.uk/showproduct.php?prodid=MY-192-CS&groupid=701&catid=8&subcat=817

Whats good, theres so many different types of memory. Much easier in the olden days when you just got the cheapest 16mb module money could buy. (Usually a choice of 3)

Corsair Dominator 4GB - 5-5-5-15
OCZ Reaper - 5-5-5-18
Patriot Viper 4GB (5-5-5-15)
Corsair XMS2 - 5-6-6-18
...

Da[]San · 16 Feb 2010 at 16:24

With the Q6600 its best to try and clock it at 8x multipler so that you are running 1:1.
So in that case you could probably get away with running 6400 RAM as its only running at 462mhz (in my case i run 4x1gb of Crucial Ballistix PC6400 at 5-5-5-15).

If you decided to run x 7x multiplier you could run native 1:1 as long as your board can also support >500mhz then PC8500 would be appropriate)

Guest2 · 16 Feb 2010 at 16:52

3.7ghz?? (water cooled?) I cant get my Q6600 higher than 3ghz (9 x 333) This is with 4x1gb OCZ platinum PC6400 at 5-5-5-15

My heatsink on the CPU, a Scythe, never seems very warm but the OCZ is roasting hot on rated 2.1volts. Almost too hot to touch

Da[]San · 16 Feb 2010 at 17:23

Its air-cooled by Megahelms and dosen't go over 60deg load at 1.425 set in bios.

Yeah i need 2.15 volts on my ram but my case is well ventilated Dragonlord K62.

Guest2 · 16 Feb 2010 at 20:22

Im now running at 7 x 429 (3 ghz)

I take it this mean memory is at 860mhz 1:1. Running fine, no errors in prime blend yet.

System info is reporting 3.86ghz for some reason??

coupe69 · 16 Feb 2010 at 20:35

Guest2 said:
System info is reporting 3.86ghz for some reason??

Probably because it's thinking you're using the highest multiplier of that chip which is 9 (9x429=3.86ish)

Guest2, you really want to be putting your multiplier back to 9 and see what how fast you can get out of your cpu.

Overclocking RAM has far less impact on overall system performance than overclocking your CPU.

Guest2 · 16 Feb 2010 at 23:47

coupe69 said:
Probably because it's thinking you're using the highest multiplier of that chip which is 9 (9x429=3.86ish)

Guest2, you really want to be putting your multiplier back to 9 and see what how fast you can get out of your cpu.

Overclocking RAM has far less impact on overall system performance than overclocking your CPU.

Anything past 3ghz seems to crash on windows startup or reset to 2.4ghz. Ill try now for 9 x 360...

Nope, crashed just after login screen with a blue screen. Beginning dump of physical memory. That was with an increase of 1.375v in bios to 1.4

Maybe something else needs changing like MCH? Or maybe something is locking the cpu to 3ghz :confused:

coupe69 · 17 Feb 2010 at 00:29

You could be limited due to running 4 sticks of memory, raising the voltage on the northbridge may well help, as well as relaxing your memory timings, you could try 5-5-5-18.

Although to be fair you're not overclocking the memory at the moment so it should be fine. Have you run memtest on your memory? Could be a dodgy stick causing the BSODs.

It may also be you just haven't got a good clocking chip, is it the G0 SLACR stepping version, I can't remember?

What mainboard are you running?

Guest2 · 17 Feb 2010 at 08:55

How do you raise voltage on the northbridge?
I have tried 6-6-6-18 before but didnt seem to do anything different, i will try again tonight though

I ran memtest on the memory when at 800mhz 4-4-4-15 and all was fine. I then clocked it to 860mhz 5-5-5-15 and all checked out ok

Chip is G0 SLACR stepping. Im using a Gigabyte P45 DS3P

Ill try the memory at 5-5-5-18 tonight and 9 x 360

Thanks for all your help Coupe

Guest2 · 18 Feb 2010 at 11:37

I tried 2 sticks instead of 4 @ 5-5-5-18 and 9 x 350. This was with voltage increase from 1.375 to 1.400. It restarted and got a string of fast beeps from the motherboard. I tried 9 x 345 and it got into windows but crashed after a minute or 2.

9 x 333 and 5-5-5-15 @ 1.375 vcore is rock stable though