2.26 overclock question...

[Emrys]

First of, I am new to overclocking so...I was looking at getting a GIGA GA-8IHXP with RDRAM....
The question is, since that board has a max fsb adjustment of 156 does that mean
that I will only be able to get up to 2.652. Multiplier of 17x156= 2652.
I hope not, if not, what am I missing here.
Oh yea, people say that DDR is better for overclocking, so, how much better would some DDR400 be
than pc1066 for overclocking, or not- I don't care about the price difference.
Thank you

 

[Duvie]

You are right on the math...The 2.26ghz is a p4b chip which is already set to 133fsb...Limited headroom and likely you will hit 2.6ghz with just a bit above vcore if recent results may follow...

It is true ddr will oc better, but you can adjust the multiplier on the chips...However this will reduce the ability of your chips...

Ie...

many pc800 rdram ppl if oc'd to near 133 could have pc1066 rdram....However not much above that they could no longer boot or get stability...So say if someone wanted to get 150fsb they would have to downgrade the rdram multiplier to 3x 150 for 450 or roughly pc900 speeds...they would need to get to 177fsb to get back to pc1066 with 3x multiplier...

NOw I am not sure how far pc1066 will go...It is ready to run at 133fsb with 4x multiplier....Lets say you get a good 2.26ghz it may be unlikley that those rdram chips can do anything beyond 150fsb x 4 =600mhz or pc1200..At 150 you will have to run at 3x and seriouosly underrun them....

I hope this didn't confuse you more...

If you don't plan on pushing here far or run at default speeds there is nothing better for performance...

If at 150fsb you got pc1066 to run pc1200 speeds it likely would take a cpu speed of 160fsb with 400-426mhz ddr to compete in memory bandwidth hungry apps...I say that cause this isn't always the case and some programs want the cpu speed. So what are your uses???

 

[Emrys]

Ok, my general uses are going to be gaming, and overclocking was just going to be for fun.
From what I understand, generaly speaking then, I would be lucky if I could get a 2.55 overclock out of the cpu
because of the ram(it being the limiting factor) and the max fsb of 156 on the board realy won't matter?
Also, can I assume that the people that are getting to 3ghz with the 2.26's are downgrading the ram, resulting in lower bandwidth?
So is the only chance for someone to get to 3ghz is more or less by droping the ram multi, and using DDR?
I'm proly lost completely on this...
I would like to get the CPU as high as I can, but I don't would prefer not to downgrade the ram, so what would your suggestion be
for a set-up. Performance is key.

 

[Duvie]

You need to go out and do some research on pc1066...I may have overstated its ability...it may not even be able to run at pc1200 speed, or it may be very certain brands that can with a bit of luck....

Honesty to run ddr ram at high levels near pc1066 levels you will need to run 400+mhz ddr...The limit of 166-170 is probable as many have reached this...So that would be 2.82-2.89ghz....


So:

Likely pc1066 limit with 4x multiplier.....145-150fsb so 2.47-2.55ghz

Likely limit with pc3200ddr (corsair)......166-170fsb so 2.82-2.89ghz w/ 3:4 ratio 175-180 or 2.98-3.06ghz w/ 4:5 ratio...do reasearch most boards will offer only one of them...4:5 gives you more hope with a high ocer, while 3:4 gives you more with a slightly more limited cpu....


If you can get cpu to 178 (very tough) or 3.03ghz you can finally get back to pc1066 speeds with 3x multiplier...

IN my opinion very tough to get to 3ghz more likely to get in range of 160-165 so w/ a 3:4 ratio you will run ddr at 427mhz-440mhz ddr or pc960 or pc990 with rdram...The ddr will score better in the bandwidth category...


Do some more of your own research on rdram as I am reporting what I have studied and make no warranties as to the complete accuracy of what I have stated....***general disclaimer**




😉

 

[Dug]

You might want to take a wait and see approach.
I've seen 5 reports now of people getting PC1200 speeds out of the Asus P4T533 w/ the 4200 rimms.
The board isn't limited to 156fsb either.

The problem of course is that the 4200 rimms are only out in 256MB pieces. But if you only plan on getting 512 total that's fine.