M15x FSB Overclocking (not only 920XM!)

[otosan]

Maximum what i can set for FSB - 137 MHz.
Any more then 137 = BSOD.
For benching/rendering with 920XM i'm using x25 for all cores, TDP/TDC 95/75, FSB 133 (sometimes 137MHz).
For games 920XM mostly running on stock.

Thx for info, you are right, i just test it, anything more than 137 goes straight to BSOD... Thx!

[King of Interns]

I just tried this and it works very well. So far I have run Prime 95 at up to 143mhz. No problem with stability. My max limit is 21x at exactly 3ghz (95C and over!) as ambient temps are getting quite toasty at 25C. TDP/TDC set to 82/70 to cope with extreme temps (any lower the multi will fluctuate - darn high ambient temps lol).

I shall continue testing. In winter with ambient temps at 19-20C I managed 25x @ 3.33ghz on 8 threads encoding for 10 hours straight sometimes with 100% load. My temps hit max 95C. Working on that temp limit Iam going to try to push past this and hit 3.5ghz and beyond as a working overclock haha! My aim is to prove the M15x can be just as fast as a machine with a 2860qm for fraction of price I think 4ghz+ will be a breeze in winter on 1 and 2 cores

Mind you this is not for benching this is for proper encoding work where I will subject the chip to 100% load for many hours. Imagine the 920xm running 8 threads at 3.6ghz+ HAHA I am going to eat sandy bridge for breakfast!

edit: tried 150mhz and got instant black screen...shame! Oh well hopefully got a few more mhz in the bank before I hit the wall. Still 143 at 28x is 4004mhz so this is an awesome development for me

[Mexic00ls]

cool my board never worked with set fsb

[King of Interns]

Well I took it to work today and taking advantage of air conditioners lol I set the laptop up in a room at 18C ambient and haven:t had much luck so far pushing the fsb at 25x

So far I have tried 140mhz fsb at 25x and it went straight to bluescreen. Seems at 3.325ghz the 920xm is close to it voltage limit. Only voltmod like slv7 has shown would help. On the plus side at 25x at this ambient temp 100% load encoding temps are maxing out at 88C on hottest core rock stable at 86/65 tdp/tdc settings.

I will try 135mhz later but it seems that might be close to max without voltmod... pretty pointless therefore using setfsb on an extreme edition chip as all you can do is find the point of max stability which would be a clock speed somewhere between 25x and 26x on all 8 threads.

Sucks that my limit is because of lack of power not excessive heat

[kaitokid1412]

this will work on i7 740qm???

[King of Interns]

On any processor. How well depends on your board.

[Mauigideon]

Is there a significant jump in performance if I overclock my 720qm in my alienware m15x?
Debating right now if I should do this with SETFSB or pay up for a new CPU...
Any suggestions?

[Mexic00ls]

i wouldnt bother with setfsb, it might not work on your board, and no the jump wont be significant. i would just get an XM processor and use throttlestop to adjust the mulitpliers.

[Mr Pras]

It depends on your motherboard revision (check the first post I think I posted about it)..

If it's A00 then you can overclock it really well and might not want to upgrade the CPU after that - it costs about $5-10 donation to ABO to try this method.

If you upgrade the CPU you're getting much better performance than even the best overclocked 720QM and you aren't sacrificing stability, but it costs a bit more that $10.

If you have the money to spare I would go for a 920 of 940XM rather than rely on an overclock

[iFanta]

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