Will my P4 Presler run at 4.25ghz !!

Flanno · 15 Mar 2006 at 18:46

Recently got hold of a system (not allowed to mention name most likely) with a 3.4 presler (800mhz fsb) and 2gigs DDR2 533mhz ram. The mobo has no overclocking options whatsoever, but I noticed when I ran CPU-Z that the memory is reported as PC4300 (266mhz) as expected, but under the timings section there is an FSB/DRAM entry of 3:4. So basically the FSB is running at 3/4 of the DRAM speed or 200mhz. All as expected.

But hang on, because of the 3:4 divider, does this mean if I install some PC 5300 (333mhz) memory (which Intel says the 945 chipset supports) that the divider will adjust my fsb to 250mhz, giving me a cpu bus of 1000mhz instead of 800mhz, and an effective overall cpu speed of 250x17 or 4.25ghz !!!

Flanno · 15 Mar 2006 at 19:03

Cheers. Thanks for the update there.

The system I got for *free*. Do you think it is worth buying some PC5400 memory, effectively increasing memory speed from 533mhz to 667mhz which I guess might offset the crap timings a bit (4,4,4,12) ? I think 667mhz is about as much as the board will support.

Flanno · 15 Mar 2006 at 19:09

What I don't understand is that on AMD systems your memory usually defaults to DDR400 speeds, and you overclock the memory with dividers and/or upping your bus or htt. But on Intel boards, does the memory always run at the rated speed independent of your cpu. I guess what I am asking is if I get memory that is rated at 667mhz will it run at this, and then the mobo will use a divider to keep the cpu at stock.

Flanno · 16 Mar 2006 at 21:26

Unfortunately my system has ZERO overclocking options. You can probably guess what company makes it, but I 'aint complaining as I got it for an indefinite period to do some Vista beta2 testing.

Flanno · 18 Mar 2006 at 00:52

I borrowed some 667mhz ddr2 and installed it in my Dimension 9150, and it runs at 667mhz - so problem is now solved. As for the post about the motherboard being rubbish - well if you got a full system for zero cost, I don't think you would be complaining, especially with a 3.4 pressler dual core which feels quiet nippy. Just waiting on a 1900xt-x now.