e6420 overclocking-dumb question

tsf

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i'm getting a e6420, GA-965G-DS3.
i'm new to overclocking, i'm confused about ddr-667 and ddr-800 ram.

i wanted to have a 1:1 ratio but that would mean 400x8=3.2ghz with ddr800, and thats out of reach with a stock cooler. but i wanted go like 2.6-2.8 ghz.

my question is: is ddr-800 worth it over ddr-667? is 1:1 really necessary?
i can do anything needed provided i use the stock cooler and not raise the voltage of any type.


thnx for any help.

(my threads may seem annoying to some, but i'm new to DIY, i'm scared!)

(p.s: someone here had a overclocking guide in his signature, it was quite useful but i lost that. will be thankful if someone link it to me)
 

Mondoman

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I've got an e6420 running at a 25% OC at 333MHz FSB and DDR2-667 ram speed. I'm using this RAM: http://www.newegg.com/Product/Product.aspx?Item=N82E16820145167 which is pretty much unbeatable price/performance-wise right now. I've been very happy with the system so far. It needs to be rock-solid, as it's being used for real work; the OC works fine with no voltage boost needed for the CPU, and temps with the stock cooler only get into the low 50sC under load (mid 30sC at idle, due to lowered fan speed setting under 40C).
 

tsf

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does that mean i can get a ddr2-800 and then underclock it (so that i can get 333x8=2664mhz)? i know it doesn't make sense but it will be stable right?
 

SEALBoy

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Yes, you can run RAM lower than its rated speed. In fact, considering that DDR2-667 and DDR2-800 RAM are normally priced close to each other (apart from the insanely cheap RAM linked to above), I'd say it's better to get DDR2-800 RAM, which you will be able to run with tighter timings.
 

tsf

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i recently read some where here that lowering the multiplyer puts more stress on the mobo than higher fsb, how true is that i dont know.

just to clarify, i'll be using stock cooler. isnt 2.8 ghz a bit much? this system should last atleast 4-5 years........ after which it will be thrown out!!


p.s: i had my mind on this ram:http://www.newegg.com/Product/Product.aspx?Item=N82E16820146118 any good?
 

SEALBoy

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Lowering the multiplier does not put load on your PC, but raising the FSB does. However, the higher the FSB, the faster everything else, so the goal is to get the FSB as fast as possible, and then lower the CPU multiplier if the CPU can't manage its new speed.

As for the RAM, try these. They run at a higher voltage, but they have lower timings, giving you faster RAM and more overclocking headroom.
 

deceneu

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I have the GA 965G DS3.
the 800 ram is better
I use A-DATA vitesta extreme edition 800+
it has micron chip and is dirt cheap
2 Gigs for 100 bucks
 

Mondoman

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The CL4 DDR2-675 Corsairs I linked to are IMHO better than the DDR2-800 CL5 RAM from your last post. If you're going to be running your CPU at 333MHz FSB, the performance results from the MadShrimps article (see below) suggest that running RAM at DDR2-800 may actually give lower performance than running at DDR2-667, especially with decent latencies (CL4 or better).
http://www.madshrimps.be/?action=getarticle&number=1&artpage=1962&articID=472
 

bkiserx7

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i was kinda lookin forward to these:

http://www.newegg.com/Product/Product.aspx?Item=N82E16820146118

http://www.newegg.com/Product/Product.aspx?Item=N82E16820231098

since it is a 965G mobo, i think it would be better to have a 1.8V ram. i probably would stick around the 2.6ghz area, so i wont need to change volts.


thnx for the inputs.

i would go with http://www.newegg.com/Product/Product.aspx?Item=N82E16820231087 ddr2 800 kit with 4-4-4-12 timings, set your fsb to 333 memory to 667 and try and tighten the timings up to 3-3-3-10 with the rated voltage of the memory and stock 1.35 V on the CPU. run this app in windows overnight to test your memory stability http://hcidesign.com/memtest/MemTest.zip. C2Ds and 965s run best with a 2:1 fsb:memory clock (eg 1333 fsb:333 memory). Note my sig 2000 fsb:500 memory
 

Mondoman

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... run this app in windows overnight to test your memory stability ...
You'll get a more thorough test by a two-stage process: 1) Run memtest86+ from boot and 2) Run Orthos under Windows.

... C2Ds and 965s run best with a 2:1 fsb:memory clock (eg 1333 fsb:333 memory). ...
That would seem to be either a 4:1 ratio or a 1:1 ratio, depending on how you interpret it. :wink:
Do you have any links/data showing that performance is best at a specific fsb:memory bus speed ratio?
 

bkiserx7

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... run this app in windows overnight to test your memory stability ...
You'll get a more thorough test by a two-stage process: 1) Run memtest86+ from boot and 2) Run Orthos under Windows.

... C2Ds and 965s run best with a 2:1 fsb:memory clock (eg 1333 fsb:333 memory). ...
That would seem to be either a 4:1 ratio or a 1:1 ratio, depending on how you interpret it. :wink:
Do you have any links/data showing that performance is best at a specific fsb:memory bus speed ratio?

lol i was meaning to put the fsb pre-quad pumped numbers like 1:2 fsb:memory 333:667 & 500:1000. I know i read it somewhere and saw the benchmarks for it. It has to do with memory strappings.... I'll try and find the article.
 

Ay_Gov

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I actually have a noob question along these lines as well. I'm interested in getting the 6420 along with some DDR2 800 and then trying my hand at some overclocking. However, one of my friends is telling me to wait until they release chipsets that support a higher memory frequency because the DDR2 @ 800mhz would be bottlenecking the 6420 @ 1066mhz. Having read loads of stuff on here and elsewhere about actual FSB and rated FSB I'm beginning to think that this is not the case since if we consider actual speeds the DDR2 800 runs at 400mhz and the 6420 runs at 233mhz but I'm not completely sure if I'm right in this thinking and would be very greatful is someone could give me some help with straightening this out.
 

bkiserx7

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A good OC guide, definitely.
The reason I asked about ratio was that the MadShrimps article testing (975X chipset) indicates that performance goes up with increasing memory bus speed above the 1:1 clock:clock ratio, with the likely exception of speed being set one "notch" above 1:1 (e.g. DDR2-667 where DDR2-533 is 1:1).
http://www.madshrimps.be/?action=getarticle&number=1&artpage=1962&articID=472

read it real quick (at work) and i think it's on the same lines as what i am saying; keep memory synchronous to the fsb.
 

bkiserx7

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I actually have a noob question along these lines as well. I'm interested in getting the 6420 along with some DDR2 800 and then trying my hand at some overclocking. However, one of my friends is telling me to wait until they release chipsets that support a higher memory frequency because the DDR2 @ 800mhz would be bottlenecking the 6420 @ 1066mhz. Having read loads of stuff on here and elsewhere about actual FSB and rated FSB I'm beginning to think that this is not the case since if we consider actual speeds the DDR2 800 runs at 400mhz and the 6420 runs at 233mhz but I'm not completely sure if I'm right in this thinking and would be very greatful is someone could give me some help with straightening this out.

you are not going to bottleneck your 6420 with ddr2 800. read the article linked by Mondoman http://www.madshrimps.be/?action=getarticle&number=1&artpage=1...&ar
 

bkiserx7

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but as he notes at the end
The Core 2 has a front side bus (FSB) speed of 266Mhz x 4 (Quadruple) ?1066Mhz?, the ram is running at 266Mhz x2 (Dual Channel) x2 (DDR) = ?1066Mhz?, so with PC4200 memory and FSB are running synchronized. When you use PC5300 you are no longer running synchronous with the FSB and a memory divider of x1.25 (5/4) has to be used. The older Athlon XP from AMD also displayed this decrease in performance when running memory asynchronous due to its short pipeline, where memory latency is more important then memory bandwidth. With the Pentium 4 the pipeline was longer and the effect of running asynchronous which increased latency was masked. Core 2 technology marked Intel's return to a shorter pipeline and thus is more similar to the Athlon XP than the Pentium 4.

By running the memory synchronous to the FSB you have the least amount of latency and thus performance is at its best. Why is PC6400, which is also running asynchronous, faster then? Because the memory speed is now that much higher that it compensates for the loss of running asynchronous and overall performance does increase. PC5300 worked great with Pentium 4 but it should be avoided when running Core 2, except when you plan to overclock. PC5300/6400 will give you the extra headroom to increase the FSB while keeping memory synchronous.
 

bkiserx7

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so back to the OP request he wants to run stock cooler with stock voltage at 2.6 - 2.8. I say 333*8 = 2.67 with 1333 fsb, and he pair that with the 675 corsair memory linked or get the 4-4-4-12 g.skill 800 linked and step down to 667 with 3-3-3-10.
 

Mondoman

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but as he notes at the end ...
By running the memory synchronous to the FSB you have the least amount of latency and thus performance is at its best.
Why is PC6400, which is also running asynchronous, faster then? ....
The two statements contradict each other (if 1:1 really gives the *best* performance, then DDR2-800 would be *slower*). Sorry, I should have pointed out that the author drew erroneous conclusions from the data. I'm just so used to looking at data to make my own conclusion that I often skip the "analysis" text...