I have already come here looking for similar answers before, and the responses I have gotten were very helpful. But I am now more educated then I was before and I feel I can ask better question now then I could before. So if anybody remembers me posting another thread (I doubt it), then forgive the redundancy.

I am going to get the E8400 woldale processor, a biostar Tforce motherboard http://www.newegg.com/Product/Prod [...] 6813138122 (this is supposed to be a good overclocker even with it limited bios settings I've heard), but the RAM is still the most indeterminate part of that set up. Right now all I know is I want four gigs for my 64bit windows operating system.

The thing is, I am really interested in getting high overclocks without pushing up the core temps very high at all. I've heard of people being able to hit 3.6ghz or higher with their E8400s, without changing core voltages, and I want to do the same. I would like to see a max overclock of about 4-4.2ghz with a air cooled system. I have heard of people doing this as well. The surprising thing for me has been, a lot of the overclocker reviews I have read say they only utilize DDR2 800 memory to get their speeds. However, I've been told that you really need DDR2 1066 memory or higher to get the most out of your system. How true is this?

Before posting I tried reading many very technical guides to understand what I needed to buy. I really found them very difficult to understand. The problem is I have never overclocked in my life, and while I plan on learning when I get my new computer, right now I need to know what I need to buy to put myself in good shape to do it later. If all goes according to plan I should be buying everything for my custom build in 2 weeks. I'm getting a xiggy cooler so if I have to push up core voltages that is ok. I have everything selected but I have the most doubts about the RAM.

So anyway, how much of a difference is there between DDR2 800 and DDR2 1066 RAM? Could I get the performance I am looking for out of the much cheaper DDR2 800 RAM? I have noticed that most higher speed RAMs come with a higher standard voltage. Does this mean that if I get a slower RAM with a much lower voltage I can overclock it to close to the same speeds? Would DDR2 RAM with a cas latency of 4 and tight timing be worth the extra cost if I went the slower RAM route? I appreciate any clarity in this. I want to buy the right materials.

Also, if anybody has a good, but detailed guides to how RAM effects your system, especially in respects to overclocking, I would be interested in reading it. Thanks all for your patience and your answers

It really depends on how far you want to oc. Good ddr2 800 can reach 1066 speeds with a voltage bump, heck even my budget 800 goes to 900 without any extra voltage. And the 1066 usually run at a higher voltage too, 2.1v is common, therefore most are just overclocked 800 anyway.

Before overclocking a core 2 you should understand how the multiplier and fsb work together.. (numbers here may be a hair off)
the e8400 has
FSB 333.25mhz
multiplier of 9

The actualy speed is deteremined by the FSB x multiplier which gives you roughly 3.0ghz

With intel core 2 the FSB is quad pumped so 333.25 x 4 gives you a 1333mhz fsb.

Now keep in mind that ddr2 memory in dual channel doubles it's speed. Also ideally you want the memory speed to be the same as the system FSB. As ddr2 800 will yield 1600mhz of bus speed while ddr2 1066 will yield 2132mhz of memory speed, both options at stock speed are overkill for a core 2 system.

Now with the wolfdale the only means of ovcerclock is to increase the fsb. To hit 3.6 ghz you would need to increase the fsb from 333.25 to 400.

Now remember the actual FSB speed is quad pumped. Now that your fsb is now 1600mhz (400 x 4) you will need 1600mhz of ram speed in order to keep up. Hence ddr2800 (800 x 2 for 1600mhz) will do nicely here.

Some however may prefer to use the faster ddr21066 to be on the safe side. as ddr2 will be pushed to the max and especially when using 4 sticks of memory ddr2800 may not be stable.

the thing with ddr2 1066 is that its guaranteed to run on those speeds, with the exceptions of fault products
ddr2 1066 is only really needed if your planning on getting close to a cpu freq [bios setting] of 533, which might happen, but is highly unlikely without proper cooling.

e8400 max multi is 9, and stock cpu freq is 333, 333*9=2997... to reach an OC of 4ghz without changing the multi is a CPU freq of 445*9=4005mhz and thats an fsb of 1780mhz[445mhz*4]...you would only need ddr2 890[1780mhz/2] to get a 1:1 ratio to prevent any bottleneck...
so to put it in simple words, ddr2 800 wouldn't have to OC that much to keep you in a good range, just get good ram with tight timings, and low dram voltage, and you should be fine with ddr2 800... you can get ddr2 1066 and underclock it which should give you similar results, you can tighten timings and lower the dram voltage, but you'll spend a little more on that...your choice really

i personally would go with the ddr2 1066...no real reason though

u only need 1066 if u plan on getting 533 fsb which would equal 4.7GHz LOL! somehow im doubting that's possible... just get some GOOD QUALITY ddr2 800 and if you feel the need to go above 400FSB, loosen the timings a bit and pump that fsb!

mothergoose

This is a post I wrote for the following thread: http://www.tomshardware.com/forum/ [...] o#t1765557

Oh good, this helps a lot. Psykhiq your explanation was very illuminating. I never have understood the whole multiplier thing (not having to manipulate it yet), but I think I have a better idea now. From what I have understood from all of your responses, is that in order to reach the clock speeds I want I need to achieve a speed that is some where between 800 and 1066. It is possible to overclock DRR2 800 RAM to that speed and so I should be in good shape if I buy something of quality. These mushkins look very good for that right?

http://www.newegg.com/Product/Prod [...] 6820146731

So with the RAM speeds and voltages considered, how far can I push the fsb of the processor before it becomes unstable without a voltage change? Would the RAM speed effect the relative "free overclock" I could expect?

nah the timings arent as good as these modules....still if you want uber savings i guess that kit would be alright... just hope ur not getting it purely cos of 3dmark vantage bad choice if thats the deciding factor lol.
have a look at these:
http://www.newegg.com/Product/Prod [...] 6820220293
http://www.newegg.com/Product/Prod [...] 6820146726
http://www.newegg.com/Product/Prod [...] 6820231192

the second link....the mushkin i would recommend only if the 3dmark vantage IS the deciding factor lol... i like the look of that patriot viper personally.

Ok, but what attracted me to the mushkins was was the low voltage in addition to the fact that it had good timings. The 3d mark is really a added bonus is guess... not really something I care about. The links you posted had a lower cas latency but operated .3 volts higher. Is that better then 5-4-4-12 timings at 1.8 volts?

EDIT: Seeing as how I want to overclock them anyway?

well if you wanted to overclock them, they should operate at them same specs at 900MHz... any higher and you will probly have to loosen the timings a little. the lower the timings at stock, the better.

I bought 1066 but could never get it to run well at that speed. I probably could have RMAed it but I really never wanted to run the FSB farther than 400.

I had my P5Q-E and E8400 up to 533 FSB though. It was just too unstable to do anything in XP beyond looking at temps and checking CPU-Z.

In fact, I couldn't find anything above 400 that was stable, and I'm sure it's OCZs fault I only tried for a few hours though.

My point really is that it's always a dice roll. I paid extra money for something I didn't need (2x2Gig OCZ Reaper 1066) and only got 800 RAM. You could pay for 800 and it might OC to 1066 no problem.

Rather than starting my own topic I figured I would jump on here as my problem is near identical.

Recent bought and built

Asrock P45R2000 Wifi
E8400
Decent CPU Cooler (Asus)
2x2Gb OCZ DDR2 1066 Reaper
Gigabyte 4870

I never had the opportunity to overclock any of my previous builds, but after some research I bought these to play around.
I have read a number of guides and searched a multitude of forums and I am still clueless as to what I need to do.
The Motherboard came with an OC tool. So rather than playing with BIOS settings I tried to use it.
However, when i change the FSB above 333 my system crashes.
I figured I could achieve the 3.6 Ghz many others have posted.

FSB to 400 should equate to 3.6? right?

The OC tuner allows me to change
CPU Frequency
PCIE Frequency
CPU Ratio (multiplier)
Plus voltages

Do I need to change any other settings? Something in the Bios?

I had been concerned over the temperatures, and cleaned and reseated the cooler with A5.
Realtemp shows Cores are 39C at idle 52C using prime95.

I have no problem getting good FPS in the games I play, I just wanted to push it to 3.6Ghz since I should be able to. And I am not usually stumped by a technology problem. Its messing with my head.

Any advice would be greatly appreciated.

Bob

You should be able to overclock a E8400 to 3.6 with stock voltages.

Just 400Mhz FSB x 9

Your temps are a bit on the high side. Should be low 30s idle, or mid 30s with stock cooling.

What about your RAM? What is it running at now?

Use CPU-Z.