overclocking

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andrewsvalesen

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ok here are my specs.

Asrock daul 939 skt
3800+ AMD 64
X800 GTO
and 2.5 gigs of ram.

I've been told that DDR restricts my overclocking ability.

If I go with these

http://www.newegg.com/Product/Product.asp?item=N82E16820161633

and get 2 gigs of that, will I be able to overclock much better?

I mean will it really make much of a difference?

I have a 550W Powersupply, with High Amps. And I have cooling down with 1 CPU cooler, 1 GPU cooler, 4 Fans, and Zalman Super grease (better than artic silver apparently)


I also have heatsinks for my ram..

Once again, how much would my overclock jump?

Like go from 3 to 4 ghZ? or what?

I'm low on cash, and I'd probably have to sell some stuff, but I want the ultimate overclocking I can get from this Rig.


Thanks.
 
No, Im pretty sure Your not using AM2 so DDR2 will not work on your motherboard. And no you will not get another Ghz out of the OC. For that you would need Phase change or something...
 
Your going to buy new RAM anyways so go get some OCZ or Mushkin PC3500 or PC4000. Get Twin sticks. If you try to mis and match memory you won't get as far as you would have liked. Also, If you don't buy new memory leave the Gig Sticks in and take out the Single 512 so it will then run in Dual Channel.
 
Ste said:
... Im pretty sure Your not using AM2 ...

*hint*: "Asrock daul 939 skt" :)

Also, Ste's completely right, DDR2 won't work. DDR2 is overrated anyway, so don't worry.
 
are the ddr 500 good for ocing?

That and... How much will going ddr 400 differ from going ddr 500 speed-wise.

Is it really worth the extra 100 bucks? (that ill be spending)

I'm low on budget.
 
Ok buddy, here's the deal. I want to make sure you understand what you're going for.

AMD CPUs don't have a conventional FSB, but rather something called a "HyperTransport" bus that has its own multiplier (5x in this case) and is also double-pumped (think DDR). That's why the CPU is advertised with a "2000Mhz HT": 200Mhz (base) x 5 (multiplier) x 2 (double-pumped) = 2000Mhz. An Athlon64 3800+ runs at a stock 2400Mhz, which now you see as being 12x200Mhz.

Now, the multiplier on the CPU is locked, so what you do to overclock is increase the base HyperTransport (HT from now on) frequency, ie: make it higher than 200Mhz. This will overclock your CPU and also your memory. So when you're using slow or value RAM, it will be the memory that limits your ability to increase the HT any further.

So what you're looking for is memory than can run at more than 200Mhz. DDR-400 is designed to run at 200Mhz (remember *real* speed is half the DDR advertised speed). If it's value RAM, you won't be able to push it much further than 200Mhz. On the other hand, DDR-500 is designed to operate at 250Mhz. This means you'll have at least 50Mhz of room to overclock the HT bus.

If you install DDR-500 RAM with your Athlon64 3800+, you'll notice the motherboard will set the memory multiplier to 5:4, so that it can run at its designed 250Mhz (200Mhz * 5/4 = 250Mhz). Here you have two choices: just increase the HyperTransport frequency and hope the RAM can go beyond 250Mhz - OR - decrease the memory multiplier to 1:1 (memory will now downclock to 200Mhz) and raise the HT ... this way the memory will only start limiting your overclock when the HT goes past 250Mhz (already a 25% increase), which would take your CPU to 12x250Mhz = 3Ghz, if your motherboard can handle it.

Edit: on reviewing a few 939 Asrock mobos (since I don't know exactly which one you have), it seems the previous paragraph may have some errors. There's no memory multiplier; rather, it's a divider. I forgot DDR and older motherboards usually have dividers. So there's no 5:4 setting (the maximum is 1:1, and it goes down from here). So I'm guessing DDR-500 RAM will automatically downclock to DDR-400 speeds. This is not bad if you're overclocking though. I would've manually set 1:1 anyway.

Yet another choice would be to get high-performance DDR-400 memory, hoping it can be overclocked enough. I guess some DDR-400 modules can be overclocked to 250Mhz (DDR-500 speeds). Here they overclocked a Athlon64 3500+ to 3Ghz using Corsair PC3200XL (DDR-400) memory. The final HT speed was 277Mhz!

Try borrowing high-performance DDR-400 or value DDR-500 RAM from a friend, in order to determine how far you can push the HyperTransport bus. Then you'll know exactly what memory you need.

Lol, that came out a bit long. Hope I'm not confusing you too much.
 
DDR restricts overclocking? Could someone explain this to me on the Intel side? I'm running 1GB of Kingston ValueRAM with my P4 on an MSI 865PE Neo-2, and I've overclocked my processor 800 MHz. The thing about this board is it increases the timing on everything else too, that's why I don't understand the comment about DDR restricting overclocking.

Oh, for what it's worth, my CPU idles around 27C early in the morning, and 32C midday. Under load it only gets to around 49C. Much better than my old Celeron...
 
firemandave said:
DDR restricts overclocking? Could someone explain this to me on the Intel side?

Memory is one of many factors that can limit overclocking potential. It doesn't always restrict it. The thing with DDR is that it has low clock frequencies, and that's why it can represent the first limitation.

It's quite the same thing with Intel, except Intel doesn't use HyperTransport, just a good ol' quad-pumped front side bus (FSB). Quad-pumped just means the advertised FSB frequency is four times the real FSB speed (for instance, 800Mhz FSB is 4x200Mhz). What's important is the real speed of the bus (200Mhz being a sound value for the CPUs in that range), so it doesn't matter if it's a dual-data rate, multiplied AMD HyperTransport bus or a quad-pumped Intel front side bus.

Just as an example, tell me your exact CPU speed (stock and OCed), memory speed and FSB, so we can figure it all out.
 
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