Overclocking a locked Brisbane core X2 5000+

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hunter33

Limp Gawd
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Mar 8, 2007
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I have an X2 5000+ (locked Brisbane core, 2.6 mhz base clock) in an HTPC. It also has 4 gb of DDR2-800 Muskhin memory, a 9800GT, and an OCZ Vertex III SSD in it. It works great for most tasks and there are no plans to upgrade it right now. It does struggle some with newer games so I decided to overclock it a little. It needs to stay quiet and cool so I don't want to increase the voltage any at all. The voltage is already slightly higher than stock by default on this particular motherboard, Abit NF2-Nview, and this memory should be able to be overclocked quite a bit with no stability issues.

Last night I increased the base clock from 200 to 215 with the default 13 multiplier. This took it from 2.6 up to 2.8, essentially making it an X2 5400 instead of a 5000. Barely any difference in temps and completely stable, the CPU never got any hotter than 48C under load. The CPU and memory scores went up a bit in WEI, and I could see a 5 - 10 FPS increase testing Battlefield 3, Skyrim, and Modern Warfare 3. I left Cool & Quiet enabled (on purpose) but noticed in CPU-Z that the clock & multiplier never seemed to throttle down even after idling for a while.

Couple questions ...

Shouldn't C&Q continue to work even with the base clock changed in BIOS?

How far should I be able to increase the base clock without system instability or excess heat?

Just looking for some ideas. This machine needs to stay quiet and cool since it's an HTPC in a SFF case.

Thanks!
 
FSB overclocking on locked X2s was never a good idea, how you could consider it fully stable? make sure you run prime95 for few hours. I had locked 6000 Windsor and you couldn't move FSB 1MHz higher without BSODs.
 
I played BF3 and Skyrim on it for a couple hours with no problems, but no I am not 100% sure it is fully stable. This is a pretty mild OC so I am not too worried about instability yet.

Hoping to get a few ideas on how far it can be OC'ed without increasing voltage, and why C&Q seems to not be working.
 
13x230 worked fine for me topping 3ghz without no voltage increase. Used it like that for almost a year and never had chrashes or BSOD. Never tested with Prime or any other stress test but who cares? i played a lot of games with 24+ hour sessions with full cpu usage... No artifacting chrashing etc... So it is possible to push 3ghz easily.. And mine ran cool with stock cooling. (Athlons did not have jet motor loud coolings like phII's.)

Also the FSB increase automatically pushes your Ram frequency.
 
ShuttleMunky said:
13x230 worked fine for me topping 3ghz without no voltage increase. Used it like that for almost a year and never had chrashes or BSOD. Never tested with Prime or any other stress test but who cares? i played a lot of games with 24+ hour sessions with full cpu usage... No artifacting chrashing etc... So it is possible to push 3ghz easily.. And mine ran cool with stock cooling. (Athlons did not have jet motor loud coolings like phII's.)

Also the FSB increase automatically pushes your Ram frequency.
Click to expand...

24 hr WOW is a bitch hahaha
 
Thanks. I might try to push it up to 2.9 later and see what happens. Not trying to do anything crazy, I just want to squeeze a little more performance out.

I had the memory underclocked a little in BIOS, so now with the CPU base clock at 2.8 the memory is at 399 mhz. It's DDR2-800 so is sitting right at rated speed. It's good quality memory so it should go a little higher with no problems.

Still can't figure out why C&Q is not working. It should throttle the multiplier down and doesn't seem to be doing it.
 
the x2 5000+ brisbanes will do 3Ghz easy. if you have a very very good chip even 3.5Ghz is a possibility and even 3.2Ghz has a good chance. i had an x2 2350 which was just a neutered version of the x2 5000+ at a lower voltage, i ran 3.05Ghz @ 1.38v(easily could of gone higher but 1.38v was all my board would go up to since it was a low wattage chip) no problem for over a year with the stock aluminum box heatsink. as far as CnQ goes, yes it will work perfectly fine since you are overclocking using the FSB. your idle clock will be higher than before but it will still function as it should.


things to remember, when you increase the FSB your ram and hypertransport clocks also increase with it so remember to lower the multipliers on them if you run into stability issues.
 
The memory is actually underclocked to around 370 mhz or so at stock, due to the ratio at factory settings. Also the auto timings in the BIOS were looser than what JEDEC data shows. As far as C&Q goes, I think the board is disabling it as soon as the "Auto" settings for ref clock & multi are changed.

I did some calculations and tried a bunch of different combos yesterday. Regardless of CPU multi this CPU doesn't like going over 275 ref clock or so on stock voltage. It also starts to get hot over 2.9 or so. (small case, very quiet fans)

I ended up with 2 different pieces of OC data that were the best balance of performance/heat, one based on the stock 13 multi and the other based on an 11 multi. The one with the 11 multi and higher base clock was putting out more heat for barely any more clockspeed so I dropped it.

I ended up with this:

216 ref clock
13 multi (stock)
4x HT multi
NB-SB & CPU-NB bandwidth forced to 16
memory set to 400mhz with timings tightened up

This gives just over 2.8 (X2 5400+ equivalent), HT in the high 800s, and 800 mhz DDR2 running right at 401 mhz which is perfect. It's giving 5 or 6 more frames in games and hardly any difference in temps. The only real disadvantage is that C&Q isn't working.

It's a mild OC, but since it's an HTPC and basically just a plaything for the greatroom that catches old parts after upgrades, I'm happy :)
 
at 216 reference go ahead and put the HT multi at 5x, the board should be able to handle 1080mhz no problem. typically this is how i change my HT multiplier.. ~230 FSB = 4x, 260 FSB = 3x 290 FSB = 2x..
 
It runs fine at 1080. I took the multi down to 4 because I've always read that HT operates fine between 800 and 1100 or so on most boards, but to keep it as close to 1000 as possible.

Any reason to take it from 864 to 1080? Figured it would just generate more heat and stress on the motherboard with no performance gain.

Thanks
 
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