I have a SLACR Q6600 sat at 2.4 in a mobo with zero OC options. My only option is to BSEL mod it to change the FSB from 266 to 333 (and the overall speed from 2.4 to 3.0 GHz).

Q1: Is that at all likely to work at default voltage?

Q2: If not what is the lowest likely successful voltage?

The reason I want to get lowest voltage is heat. It's a small system with limited cooling options - the Q6600 under Prime does get to 80C but that is fine.

with BSEL mod its a bit of a PITA to have to re-paint the conductive paint for each voltage so ideally I want to make a GOOD educated guess and have never OC'd one of these before...

1) maybe, but it depends how good the cpu is.
2) if you cant set the voltage manually then the board will use more voltage itself, so its likely that it will use more voltage than the stock speed.

You also might want to check if the motherboard supports 333fsb as the chipset may cause it to not work rater than the cpu.

Pretty much every G0 version of the Q6600 and most of the original version would do 3150MHz +/- 50MHz on default voltage in my experience however you may find issues with FSB "holes" or the motherboard's current delivery - I've found a good number of the locked down/basic boards of that era (largely designed before quad cores) struggle above ~2800MHz with the Q6600.

Thanks guys. So looks like I try it BSEL mod to 1333 on default voltage. I know the board runs fine with that as it had a FSB1333 E8400 in it before I swapped in the Q6600. Just gotta wait for my conductive paint to arrive for the mod then.

Out of curiosity why are you overclocking? Is it as bit of a project or are you genuinely in requirement of the performance gain?

Methanoid said:

Thanks guys. So looks like I try it BSEL mod to 1333 on default voltage. I know the board runs fine with that as it had a FSB1333 E8400 in it before I swapped in the Q6600. Just gotta wait for my conductive paint to arrive for the mod then.

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running a dual core at speed and a quad core at a speed is very different on 775, that is a good sign though as the e8400 is supported and its a newer 45nm cpu so the chipset might not be too old.

harry5522 said:

Out of curiosity why are you overclocking? Is it as bit of a project or are you genuinely in requirement of the performance gain?

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Well nobody NEEDS to OC... they just want to for more performance. Or are too tight to buy the chip they need...

In my case its a 2nd machine I will use for various OS - OSX, AROS (Amiga-like), Ubuntu, Android etc. It was cheap but would be nicer with a reasonable quad core. I may also run some emulators on it. I picked up the Q6600 cheap, an E5700 cheap (might see if that BSEL/VID mods to 4ghz) and upped the ram from 4 to 8Gb. I'm actually using it now as my machine while I loan my son my main machine (since he games more than I do and his had an accident involving a drink and sparks!).

Jumper118 said:

running a dual core at speed and a quad core at a speed is very different on 775, that is a good sign though as the e8400 is supported and its a newer 45nm cpu so the chipset might not be too old.

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Q45 chipset. It's a HP DC7900 SFF and rather nice actually

Hmmm, please check your trust

Plus the performance jump on a Q6600 from 2.4GHz to 3+GHz is pretty big - enough to be noticeable in normal use even.

Do miss those chips - the Q6600s I've had a play with (in terms of seriously overclocking) were pretty much bulletproof - had one running 3.825GHz and eventually 4GHz watercooled at 1.65V for like 2 years of heavy processing (game dev map compiling in the old days when it could take hours or even days and video encoding, etc.) and still working last I checked to this day.

Thanks guys.. well I have more than enough to mess around with now...

Anybody actually BSEL modded themselves? I did a few years back but seem to not be making it happen now.. wondering if my silver conductive paint is not conductinG!?

Methanoid said:

Anybody actually BSEL modded themselves? I did a few years back but seem to not be making it happen now.. wondering if my silver conductive paint is not conductinG!?

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I did it many years back on AMD CPU's, that and pin modding with a small metallic wire in the socket. I used a compound called liquid solder (a form of metallic glue for repairing circuit boards without using heat). That worked to mod the frequency and voltage ranges, google 'liquid solder glue'.

Funnily enough but shortly after posting I found further BSEL guides. One showed that I didnt need to join two points but to block one so a small slip of tape allowed me to get my Q6600 to 333FSB in minutes and now I can run 3GHz default in my "play box"... so all golden now

Yeah I've done the Q6600 one where you cover a pin before and messed around with 771 to 775 conversion but never got around to finishing that one.