Laptop OC slows?? my GPU


Hi there,

I am looking for some very specific help with my newly OC'ed Pentium M laptop.

I upgraded my Toshiba satellite pro M40 from a 1.4Ghz celeron to a 1.8Ghz pentium m 755 (both were 400Mhz FSB) and that went really well.

I later got a hold of a 1.73Ghz 740. This uses the 533Mhz FSB. I figured I would try it out and see if it improved the RAM speed to help my **** integrated Radeon Xpress 200m, and to my surprise it worked a treat.

Performance jumped about 33% as one would expect from raising the FSB.

Recently I read about the pin-mod OC that can be done to set the FSB to 533 even on a 400Mhz CPU.

Last night I did that, swapping in the older 1.8 m755 to achieve a result of 2.39GHz which is currently running stable.

My problem is that now the GPU has started running 33% less again than when the 1.73 true 533 Mhz fsb processor is in.

What the hell is going on. In 3dmark03 I checked the system details and it says that my external clock is still 100Mhz even though CPU-Z says I am running at 133mhz FSB.


I really want to keep the 1.8 running at 2.39, but my 3dmark has dropped so much (986 to 768)i am seriously considering just using the other one that gets more FPS.

Is there any way to change the external clock to 133?

I know this is a long shot but I think if I am going to find an answer its here.

Thanks in advance.


Aug 15, 2007
ya your pin mod just jumped the cpu and not the fsb of the system. Probably a multiplier mod or something.
As for fsb adjusting on a laptop, I don't know if those are adjustable in bios or if they're hard wired, in which case you need to get a detailed board diagram that'll show where the fsb jumpers are (most likely soldered in wire jumpers).
From what I could find on the net it looks as though the 740 is a much faster cpu than the 755 even with the slower clock.
I would just go with the 740..hope this helps.


I am toying with the idea to use clockgen or setfsb software tools to try and achieve better results.

It couldn't be to do with RAM latencies or anything like that could it.

Unfortunately the BIOS is rubbish and has NO settings for ram or fsb adjustments.

Its is so annoying because most of my games play pretty well ...ish on the 740. But if I could bump the CPU and maintain the faster GPU interface config I would actually be able to play with decent framerates above 800x600.

It must be possible. I will go for broke, it took me far too long last night getting the damn pin-mod in with my fat chunky fingers, to give up now.


Jun 18, 2008
lol.... last time i heard "decent framerates above 800x600" was so long ago... i think 16 november last year... yeah (that was the release date for crysis if you didnt know...) LOL.


OK, so I have put the 740 back in, and have been using clockgen and powerstrip to OC the CPU and GPU respectively.

I now have the 1.73-->2.15 Ghz CPU running @ 53C under load @ stock Volts

The GPU has gone right up from 300-->382 Mhz core. No articfacts

I have gained ~10% in 3dmark 03 from 936 before OC on this chip to 1026

I would still like to experiment with raising the "external clock" as this seems to give me the most dramatic improvements due to the GPU being bottlenecked by the RAM ->GPU bus.

I have NO idea where to start off but will try and do some more research.


Oh, and I am now playing UT2003 @ 1024x768 at playable FPS.

BF Vietnam is playable now too, but only at 800x600

Not bad for a 2 year old £350 (new, added some ram and new cpu) laptop.


Just another wee update,

Upped the CPU to 2.5 and the GPU to 400.

well worth it

CPU max temp under load 55degC

a total beast of an OC @ stock volts. and in a lappy.

I just need to find a way around the memory bottleneck.