CPU Overclocking in a Dell

[bamacre]

Link to auction listing...

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&ih=005&item=200096660457

Quote from description...

Here is the explanation for the CPU running faster than it?s original speed that I mentioned above. I have used a little known trick to fool the motherboard into thinking that the processors runs on a 1066 MHz Front Side Bus (FSB). The process of making a processor run faster than it?s rated speed is commonly referred to as overclocking. The processor normally runs at 200 FSB (800 MHz Quad Pumped) with 15x multiplier (200 x 15 = 3000) but now runs at 266 FSB (1066 MHz Quad Pumped) with 15x multiplier (266 x 15 ~ 4000).

The key to doing this modification (the mod only involves the CPU and not the motherboard) is to know what to do and perhaps the biggest challenge is finding a CPU that is capable of increasing it's FSB from 800 Mhz to 1066 MHz. I have been offering overlcoked processors in Dell systems for over a year now. Plus, I've been using a Precision 380 with 4.0GHZ processor as my own personal system since August 2005. I have had no problems at all in all this time. At this point I will consider it a trade secret on what the modification involves but I will say that it is reversible from the CPU and you should be able to find info on the internet if you look hard enough. I will also mention that the overclocking does not involve using a "hacked" BIOS or any software utilities/programs.

I have searched and for the life of me, I cannot find out how this guy does it. Can anyone help?

 

[Jeff7181]

My guess is a pin mod. Short two pins and it thinks the processor was designed to use a 1066 MHz bus. People did that with Athlon XP's too... usually used a small strand of copper wire, like from a telephone cord.

 

[bamacre]

Originally posted by: Jeff7181
My guess is a pin mod. Short two pins and it thinks the processor was designed to use a 1066 MHz bus. People did that with Athlon XP's too... usually used a small strand of copper wire, like from a telephone cord.

Ahh, I see. Well, not really, I don't understand why that works.

But I assume that's why he's only doing it to Pentium cpu's, and not C2D's?

 

[aka1nas]

He's probably picking system models whose boards can run the higher FSB speeds and pairing them with a lower end CPU that has a lower stock FSB. Then, he's either maxing the FSB in the boards BIOS if it allows so, or doing some sort of pinmod to tell the system to use the higher FSB. Alternately, maybe the model he is using has a jumper on the mobo still to set the FSB speed.

The multiplier, voltage, and other stock settings are communicated from the CPU to the motherboard across several preset pins. These pins are shorted a certain way inside the cpu to encode that information. Pinmodding involves using a little piece of wire to connect the appropriate pin(s) to Vcc or Ground.

We use to do it on Athlons when there weren't good overclocking BIOS options available.

 

[bamacre]

Originally posted by: aka1nas
He's probably picking system models whose boards can run the higher FSB speeds and pairing them with a lower end CPU that has a lower stock FSB. Then, he's either maxing the FSB in the boards BIOS if it allows so, or doing some sort of pinmod to tell the system to use the higher FSB. Alternately, maybe the model he is using has a jumper on the mobo still to set the FSB speed.

The multiplier, voltage, and other stock settings are communicated from the CPU to the motherboard across several preset pins. These pins are shorted a certain way inside the cpu to encode that information. Pinmodding involves using a little piece of wire to connect the appropriate pin(s) to Vcc or Ground.

We use to do it on Athlons when there weren't good overclocking BIOS options available.

Thanks. Ok, now that I kinda know what to search for, especially "pin mod," I'm finding what I am looking for.

Yes, the Precision 380 was compatible with Pent EE 1066mhz FSB cpu's, and certainly the Precision 390 is capable of 1066mhz FSB Core 2 Duo's.

I guess the BIOS in the XPS 410 and Precision 390 models are not ready for 1333mhz FSB, thus he's not doing pin mods with C2D's. It certainly seems possible to pin mod them...
http://sg.vr-zone.com/?i=3904

Oh well. With the OC'ability of the C2D, and owning more than a handful of new dell systems, I thought this was worth looking into.

Thanks again guys for the info.