Few quick overclocking questions

[fish99]

Just playing round with my first attempt at overclocking my CPU here, see sig for specs. I'm new to overclocking so I'm just trying something modest to start with.

So, A64 4000+ San Diego (Freezer 64 Pro)-
FSB up to 233, multiplier at 12x
RAM down to 166 Mhz (ddr333) (194 MHz with the higher CPU FSB)

CPU-Z shows CPU running just over 2.8 GHz at around 1.5V. 3DMark06 3890, SuperPI 1M 31s, Doom 3 timedemo (1280*1024 ultra) 102.7 fps.

1st Question - the vcore is going up to 1.5v max (using cool'n'quiet btw so it's varying) but I didn't change it. Is the board (A8N5X) upping the vcore automatically? It's set on 'auto'.

2nd Question - SuperPI is down from 35s to 31s, which is nice, but no improvement in Doom 3 or 3DMark06. Would I be right in thinking I'm completely GPU limited then (X1800 XT 256mb), and would I also be right in concluding that if all I'm interested in is gaming performance, then I may as well not overclock the CPU and have lower temps and smaller electric bills. In other words it's not gaining anything in gaming performance on my system with my video card.

I understand Doom 3 and 3DMark06 aren't indicitive of every game btw, some may well use the CPU more and benefit from the extra CPU speed.

3rd Question - I've heard people talk about a 'divider'. Do they just mean slowing the ram down to keep it within limits? So if you up to the CPU FSB 16% you have to slow the ram down roughly 16% to keep it running at 200 MHz and keep the system stable. My board doesn't seem to have many options for ram speed - 300/333/400 etc but not the inbetween settings.

Thanks in advance
Simon.

 

[SiriusB]

1: Turn off Auto and definately turn off cool n quiet. You may well be able to get similar overclocks with a lower vCore, but you will never know if you let the mobo do it. Cool n Quiet just screws up everything when it comes to overclocking and can cause instability.

2: I couldn't tell you what games use a lot of CPU compared to the GPU and those that use little CPU. If you are worried that you are overclocking for nothing just think of the gains in other applications other than gaming. Besides, the amount of extra power isn't THAT much and the Arctic Cooling Freezer 64 Pro is a hell of a HSF and will keep that CPU cool enough. It is doing wonders for my OC'd 4400+.

3: Yep. The divider is there to keep the RAM within tolerance. If your RAM has some overclocking headroom you can get away with higher than 200MHz but some RAM hates it!

To find the limit of your RAM simply underclock your CPU by lowering the CPU multi to something like x9 then starting from 200MHz FSB keep upping it slightly and running memtest86+ to test if the RAM is stable. You can even up the RAM voltage a little too to increase stability.

You will get to a point where nothing you do will make your RAM stable - you have found your max OC of the RAM.

My own OCZ RAM at default voltage can only manage ~215MHz but with the current divider it is only running at stock. ~15MHz is no great loss, but if I decide to push for a higher OC on my CPU it could help out a lot if I can't find a divider that will keep my RAM at 200MHz.

SiriusB

 

[fish99]

Cheers Been playing round some more and got the chip stable at 250 MHz FSB, so 3.0 GHz which is in excess of FX57 speeds and very nice for a £90 CPU Hits 52 degrees under load which seems fine to me. That's at 1.5V vcore.

For now I've left cool'n'quiet on since I can't see any sign of it doing any harm. I'm gonna get one of those power usage metre things next week so I can check if the PC really does use significantly less power with cool'n'quiet on, and if not I'll turn it off. I hate the idea of it using tons of power when I'm just browsing the web though.

Had to drop hypertransport to 4X and ram speed down even further, but I'm thinking of getting some PC4000 ram next week (I'm buying new 2GB ram anyway, it's just a question of whether to get PC3200 or PC4000), so that would let me run CPU and ram both at 250 MHz which would be pretty awesome

Also overclocked my X1800 XT 256 mb to a modest but nice 689/797.

 

[SiriusB]

That is a sweet overclock there dude! 52C is a pretty good temperature but I would watch out when the weather gets warm - although you probably wont need to worry about that until next year

SiriusB