new to Intel

[fireandsmoke]

OK,
Now that I've sold my A7N8x and ordered a new 845PE mobo, I need to get up to speed on Intel OC'ing.
So to start with the multipliers are all locked as follows
2.26 - 17
2.40 - 18
2.53 - 19
2.66 - 20
2.80 - 21
3.06 - 23
These run at 133mhz fsb, so what's this quad-pumped stuff mean? And how does this work in relation to fsb settings and dividers, etc.?
I know it's 20 x 133 = 2.66MHZ chip, not 20 x 533...
I assume that 533 is 133 x 4 or the memory speed. And when people overclock their fsb they need to slow down the ram with ratios?? Am I close? I've seen some boards that offer dividers like 4:2 , 5:2 etc and some that say 2.0x 2.25x 2.50x etc...
This part's a bit confusing for me after tweaking AMD's.
So...once I get past mem settings, it looks like most setups can hit 160-170fsb speeds...
so, 2.26(17) x 165 = 2805mhz
2.53(19) x 165 = 3135
2.66(20) x 165 = 3300
2.80(21) x 165 = 3465
3.06(23) x 165 = 3795
So, it looks like that big fat multiplier on the 3.06 and 2.8 are solid gold for overclocking, right?? I've been reading a lot of old posts trying to get up to speed on Intel OC but it's taking a while. Any help'd be appreciated.
Here's the rest of the rig.
845PE Mobo
256mb XMS 3200C2
TTGI 520 PSU
Swiftech MC478HS w/ Vantec tornado
Vantec fan control
Prometeia by Jan.
CPU - undecided
R9700 - stock
cdrw, maxtor 7200, etc.
f&s

[worthless]

The memory, at a 1:1 ratio, will run the same speed as the front side bus, so with a stock front side bus of 133mhz, you are getting 133mhz memory (266mhz ddr). The dividers are usually used to INCREASE the memory speed, as good memory can handle speeds a lot higher than your front side bus is gonna go.

So say with a 2.66ghz processor (20x multiplier), if you up the FSB to 150 you get 3ghz on the processor and 150mhz on the memory. If your memory can handle it, you might wanna set the divider to 3:4, your fsb will remain 150mhz, your cpu will continue to run at 3.0ghz, but your RAM will now be running at 200mhz (400mhz ddr). You will get a nice increase in memory bandwidth.

The higher multipliers do not necessarily mean a better overclock. Some of the lower chips are hitting 3.0 and beyond, while some of the higher chips are having trouble going over 3.0... your mileage will depend on the individual chip.

And the lower the multiplier, the higher you will have to set the FSB to obtain your desired speed, so you get the benefit of faster memory speed... Intel does sort chips based on pre-testing usually, so there is definitely no guarantee you are gonna get a good overclock on a lower multiplier chip.

I've been reading that the 3.06ghz are running really hot, so you might not get a very good overclock until you have your prometia.

[fireandsmoke]

Worthless,
No you're NOT!:)
Thanks. That makes sense. My board uses numerical ratios like 1.50, 2.00, 2.50, 2.66 which I guess correspond to 3/2 4/2 5/2 etc. So unlike AMD, you can have default cpu speed and run the memory hot...interesting. C'mon there has to be one of those chips that people are saying "it's a dog" or it's hot! It just seems like if you start with a high multi...
the 3.06 for example, only needs 174fsb for 4GHZ!!! But then with these mem ratios you could run the mem at 261 or 348 or 435 (if it can hack it)
What are the limiting factors for P4 cpu speed? If memory is not the problem, what is it? Heat?What is a good running temp(avg) for a Northwood and what's warm?
Thanks again
F&S

[worthless]

Assuming your memory and motherboard can handle the high FSBs, the main limiting factor is just CPU quality I guess... cause you can take two identical chips, and one might not overclock very high at all, even when running cool, whereas the other might go really high. Upping the voltage will help some chips go higher, it might not help another chip. There really is no way to tell without throwing it on a board and trying.

Another limiting factor is the architecture of the chip... the high multiplier chips, like the 3.06, are already creeping up on the ceiling for this core stepping. It's gonna be a RARE chip that will hit above 3.6 or 3.8 ghz without some serious cooling. It's also gonna take some serious voltage, and over volting can decrease the life of the chip significantly, if not fry it outright.

Me, I've decided to go middle of the road and get a 2.66... I feel a 2.66 probably has a pretty good chance of hitting 3.0ghz + on air cooling, and I'll still get a pretty nice memory bandwidth increase from overclocking the fsb. Of course, that won't always be the case, and I might end up with a 2.66 that doesn't wanna clock higher than 2.7 or 2.8...

As for common temperatures, I'll let someone else answer that. I live in Hawaii... so my case temperature is usually on the high side.

[fireandsmoke]

W,
Yes that 2.66 has me interested too. And that 20x multi is pretty flexible. Hawaii...ahhhhhhhhhhh. I'm in Seattle.
f&s