I know my processor...but that's about it

Hey everyone, here's about all I know: I've got a E8400 (45-nm 3.0ghz intel) set, but that's all. I'm building this machine for both gaming and OCing. I need a new hobby, and hardware is it.

So I've been doing some reading, at it seems pretty clear that the GeForce 8800 GT is the card to go with. Probably I'll end up running 2 in SLI, but I'll start with one at first. So I want a motherboard that will run SLI.

Second, since I'll be overclocking (and here's where some confusion on my part sets in), I'd like to get good memory to go with the board. That means DDR2 or 3 (for now it will probably be 2, but I'd like a mboard that can use 3, since someday...). But then I still don't totally understand how to match the memory with my CPU's FSB. From what I gather, the CPU mhz is the combination of the FSB * the multiplier. But the 8400's FSB is listed as 1333 mhz. Is that the combination of the two cores? (i.e. each core is 667 mhz FSB (that seems high) with a 4.5 multiplier?) So what type of memory should I be looking at? DDR2 at 800 or 1066 mhz?

Lastly, I'd like to have SATA drives and be capable of RAID.

So - what sort of motherboard / memory should I be looking at, given everything I said above?

Thanks a ton!
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  1. Overclocking c2d 101:


    To calculate cpu speed:

    1333/4=333.25*9=2999.25 or 3ghz stock

    To calculate ram speed:

    333.25*2=666.5 or 666mhz stock

    By default, the mobo will see the ram as 666 or slower speed. In order to o/c the cpu to 4ghz:

    cpu: 445*9=4005 or 4ghz

    ram: 445*x=890 or 890mhz

    You'd need at least good 800mhz ram to do that. Or faster ram. Ballistix, Firestix, G.SKILL HZ, etc. are the best overclocking ram.

    680i can do up to wolfdales. 780i can do yorkfields. Are you upgrading to Q9XX0 when they come out?
  2. Thanks for the feedback. Also, I might just steal your specs ;)

    I don't get why we divide by 4. Other than that, I get the math now (for both processors and memory).

    As to moving to the Q9 series - I probably will eventually, but it seems like that might be a ways down the road. So I should probably go with a 780i, do you think? Who makes the best 780i for experimenting?

    Thanks for your feedback, it's quite helpful!
  3. Id get an 8800GTS 512mb, it has better cooling and a bit of performance over the GT.
  4. You divide by four because Intel "quad pumps" their FSB. What this means is that for each clock cycle, they are able to send 4 bits of information.
  5. 4745454b said:
    You divide by four because Intel "quad pumps" their FSB. What this means is that for each clock cycle, they are able to send 4 bits of information.

    Ahh! And it does this no matter how many cores there are?

    Is that part of the reason quad cores don't scale quite as well? Or is that just because many apps aren't multi-threaded very well?
  6. robertito said:
    Id get an 8800GTS 512mb, it has better cooling and a bit of performance over the GT.

    Eventually I'll be providing my own cooling, but I'll look into it!

    What's the difference between the 8800GTS 512 and the 8800GTS 640? I mean, obviously memory. Is that all?

    And would it be better to do 2 x 512 or 1x 768? (That opens up a whole 'nother can of worms, I know)

    Thanks again - eveyone's been really informative.
  7. Yes, it does this no matter the number of cores. Lets review what I'm trying to talk about. The FSB is the link between the CPU and the northbridge on the motherboard. Like many things in the computer, there is a frequency at which this link runs at. Many Intel CPUs use a stock frequency of 333MHz.

    Every frequency looks basically like this. In the olden days, we could only send one bit during one frequency/cycle. We eventually learned how to double pump it, or send two bits during one frequency. This allowed us to run the FSB at 100MHz, but we could move the same amount of data as if the bus was running at 200MHz. (I think the bits are transferred during the leading and trailing edges, but I could be wrong about that.) Intel quad pumps their bus, meaning they can send four bits per cycle. As you can see, I never once mentioned cores, as it has nothing to do with cores.

    As for scaling, some quads scale a lot better then others. We Intels quads you can't turn any cores off, so we can only guess how adding cores helps. I believe it was toms that did the article showing how phenom scales quite well with more cores working. It is true that you don't get perfect scaling with added cores, I'm not 100% sure as to why. Current coding certainly does play a part in it, I would assume logic inside the CPU play another. In a single core CPU, the CPU does the work. In a multi core CPU, it has to be assigned to a core first, and if CPU1 is waiting for an assignment, then it won't scale perfectly.

    EDIT: Edited for spelling.
  8. Is OCZ good ram? Also, what's a good 780i board for overclocking?
  9. Intel FSB has always been quad-pumped. (x4)


    DDR/DDR2/DDR3 has always been double-rated. (x2)


    The high-end OCZ is good.

    EVGA 780i.
  10. akhilles said:
    Intel FSB has always been quad-pumped. (x4)

    Not true. Even the first Pentiums didn't use pumping. The first Intel consumer level CPU to support "pumping" was the first P4. (all of the P3's used a real 133MHZ FSB.) The P4 dropped the true speed down to 100MHz, but pumped it up to 400MHz. The amount of pumping has stayed the same, but the true speed has really gone up. They now have 400MHz true speed chips out, 1600MHz effective.

    OCZ ram is pretty good, high end or not. (Obviously if you buy the cheap stuff, its still cheap stuff. Don't expect miracles.) OCZ is a good company, you shouldn't have any problems.
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