E6600 OC wall?

[JoeHutton]

Hi all,
Been trying to overclock my system for a while now. Managed to get 3.25ghz out of my E6600, with a 1:1 ratio that means my 3gb's DDr2 800mhz RAM is running at 730mhz (not ideal )

I have used 9 x, 8 x and 7 x multipliers with my CPU but i cant get anything stable over 365 FSB, its like I have hit a brick wall???

360 downwards my system is completely stable. From 370 - 399 my system will boot up but is unstable under loads. and anything 400+ wont even boot and I have to clear my CMOS usually (btw, I have a Asus P5b mobo).

All the settings that are relevant to overclocking have been disabled as per the numerous guides I have read so it can't be that.

Heres a little more info on my current OC:
E6600 @ 3.25 ghz (roughly)
CPU voltage @ 1.500 (although only needs 1.475 to be stable)
RAM = OCZ 2 x Platinum + 1 x OCZ Crossfire @ 730mhz CS4 timings (timings wont run any higher or lower)
Ram voltage at 2.1v (wont allow me to go any higher for some reason?)
Current FSB: 365
Current multiplier: x 9


I have been tweaking with these settings for hours and I can't seem to get anything better than that which is stable (under Orthos). Am I just unlucky in getting a not very overclockable cpu? Or am I doing something wrong that you pro's can tell straight away ?

I know 3.25 is child's play for this CPU and I would really like to get it to 3.4-3.5 at least but I need some help

Some other points that may be useful i dunno?:
- A few days ago I could run my RAM at 900mhz by using a 4:5 ratio but now after messing around with stuff in the BIOS (then reverting it back to original OC settings) it gives me blue screen saying that it needs to shut down to prevent damage to my system.
- the memory re-map feature, when enabled my system wont recognise 3 gigs of RAM, only 2, so it has to be disabled, which is contrary to the guides that say if u have more than 2 gigs... to enable it?
- I can't put more than 2.1 v into my RAM, BIOS wont let me, is there a way around this? All three sticks have heatspreaders on them and I have bought a memory cooler which blows 2 fans directly onto them so i'm pretty sure I could increase the volts by 1 - 2 notches..?


1 more question - As overclockers yourself, would you sacrifice some of the CPU speed to increase the RAM speed, because at the moment my RAM is underclocked and maybe I should sacrifice some FSB so I can get it back up to stock speeds..?


Thanks for your time, advice would be really appreciated

Joe

[s_kinton]

It may well be that you are at the limit of your board/CPU. If you've lower the multi and increase the fsb you will find the max stable fsb of the board/cpu, as by keeping the multi low, you'll keep the cpu clock speed low with the only limiting factor being the board.

I would also try removing the 3rd stick of ram and overclock with just the 2 sticks of OCZ Plat in there. Having 3 sticks of ram in the PC is not ideal for overclocking. Try with the 2 and post back.

[DougMcDonald]

Hi Joe,

I experience a very similar problem with my P5B and E6600.

I get similar problems with the FSB's you are talking about. Don't seem to be able to fix it with multipliers etc.

I can get things to go faster than 360 or so in FSB, but then my PCI-e bus drops from 16x to 1x for some reason.

Same as you I wondered what could cause this type of thing, I can only really blame the mobo.

Regarding the memory remap, I have 4GB in 2x2GB sticks, and i had to enable to remap to allow XP64 to see all 4GB's.

I will post more info when I get time, at work at the moment.

I have gone a half way house with this, running fsb at about 330 and running the ram at 5300 instead of 6400 on the bios, this was I think the ram gets about 7xx something which doesn't seem to underclocked and the processor stays nice and stable.

I will update those number above when I get home!! can't remember off the top of my head

Short answer is that I think the board has the problem

[Krumm]

I've been able to get up to 3.5ghz on my e6550. The ram's at 1ghz too. I must say I'm surprised that you can't go that high - my maximum multiplier is 7x

[Salazaar]

Have you worked out if its the board, the memory or the CPU which is failing? I'd drop the multiplier on the CPU to something nice and low first. Then (presumably the memory should be able to get up to full speed without problems) build up the FSB until you find out what the limit is. Then you can use higher multipliers and dividers to find out what the respective limits are on the CPU and memory.

It sounds like it might be the FSB limiting you (since the CPU won't boot on a x7 multiplier), have you tried upping the northbridge voltage at all?

[JoeHutton]

Thanks for the quick replys
@S_Kinton
The maximum FSB I have tried with any multiplier is 500, is there any point going higher, because I heard 550 was the limit on p5b's and that is straining it...?
Hmm I was hoping someone wouldn't say its because of the RAM, just installed that new stick, lol
i had some problems at first with it, being very unstable, but then I changed the clocks to CS4 (was CS5 before) and I increased the memory voltage to 2.1v, then it worked fine.

@DougMcDonald
I picked the P5b because I thought it was good for overclocking..lol, or did we just get unlucky?

@Salazaar
The memory is all good according to several (12 hour long) tests.
I don't know how to test the CPU but I know its running at around 30C idle which is pretty cool, and around 45C under heavy load. It is also very stable at anything <3.3ghz.
I haven't tried the 6x multiplier yet because I thought that would push the memory way past its desired speed to get any decent level of CPU speed.
I increased the Vcore to 1.5 (stock = 1.375), and I heard that anything higher is dangerous for the chip so I haven't been brave enough to go any higher than that.


Will try out some more stuff, thanks for the advice so far, will post screen shots of my BIOS which may trigger some ideas, lol

[Salazaar]

Sorry, I don't think I explained quite right. What I'm suggesting is to drop the CPU multiplier and the memory divider to run them as low as possible. That way you can up the FSB without running out of headroom on the CPU or memory and find out exactly how far you can push the FSB.

Once you've found out how far you can push the FSB you can try adding a little more voltage or skip staight on to doing similar tests for the CPU and memory speeds.

I can get 400Mhz FSB out of my P5B but I'm limited by the memory because it doesn't like running faster than 800Mhz and I haven't got a lower divider to use. My CPU also starts to give up after 3.2Ghz so I'm using a x8 multiplier rather than x9.