Quick question about memory dividers and other stuff

[Zelaya]

I've been doing a lot of research for my new setup; basically my question is, if you need to use memory dividers in your overclock of your cpu, by using the divider are you losing out on some overall system performance? If so, how much would I be missing out on?

I'll be upgrading to an Opteron 165 with an Asrock 939 SATA2 mobo (need that agp). The overclock I'm looking for is fairly modest I think (2.4ghz). This will all be done on air etc..

I have a choice of 3 different pairs of ram to use, Corsair XMS pc3200, Kingston Hyper X Series ( i think it's like a 4200?), and Geil pc 3500 or 3700 (not entirly sure). You guys think 2.4 is something easily achievable with the ram above? Most of my other components are quality parts as well: Antec True Power 420w psu, Radeon X800XTPE, and a Sound Blaster 2 Audigy Plat. sound card.

Don't know my stepping yet, as I'm waiting for the cpu to come in (which is some time later today, can't wait).

Well I think that's all of my question, hopefully one of you guys can give me some good answers! Thanks for the help in advance.

 

[Leper Messiah]

2.4 would need 9x270 or something close to that. 9x267 I think. So...166 divider is like 245 MHz, thats too much for all but the best ram and decent timings. 133 divider gives you like 180MHz, which any ram can do with 2-2-2-5. Or you could use 8x300 if the board will do that and run a 133 divider and get your 200 MHz back.

 

[Pyrokinetic]

If I am correct, the Opty 165 is a dual-core 1.8Ghz? That would mean a stock multiplier of 9. Thus to get 2.4GHz, you would have to a least go 267x9 (as long as your board can post and be stable). Using the 166 memory divider in such a scenario, you would achieve about DDR437 (267x9=2403; using the 166 divider you would divide by 11; 9/(5/6)=10.8 or 11; thus you get 2403/11=218.45 or roughly DDR437).

If I was you, I would go for 2 gigs of ram, and a speed of DDR433. Check out the Corsair XMS TWINX2048-3500LLPRO:
http://www.newegg.com/Product/Product.asp?Item=N82E16820145594
Or if you are happy with 1 gig:
http://www.newegg.com/Product/Product.asp?Item=N82E16820227052 or
http://www.newegg.com/Product/Product.asp?Item=N82E16820144141

The memory divider in this case will not slow performance because you are still above DDR400 and retain low latency timings. By not using the divider and going 1:1, you would have to deal with a DDR of 500+ which would require much slower timings (or Mushkin Redline XP4000, which is no longer available and requires high voltage and active cooling). So you now have the choice of high bandwidth memory which uses slow timings; or low latency, which uses fast timings. I would recommend the latter, as AMD chips with the on-chip memory controller perform better with faster memory timings versus huge bandwith (That is why AMD still uses DDR memory instead of DDR2).

Getting to 2.4GHz will depend more on the ability of your chosen board. Carefully check that your board can do 267x9. 2.4Ghz out of a 1.8Ghz chip would be a 33% overclock, which is not a modest overclock. Newegg reviews of this board indicate it is not easy to overclock with, so read the reviews (there are a lot) to see if you REALLY want to use this board. (I would advise against it.):
http://www.newegg.com/Product/CustRatingReview.asp?Item=N82E16813157081

Just a pointer... if you really want to overclock, get a board that can do it. The ASRock is a compromise board that provides a bridge between old and new tech. Therefore, it is designed primarily to be stable. If you plan to go PCIE in the future, buy a good overclockable PCIE board now and ditch the AGP. You can always buy a cheap PCIE vid card now until you can afford what you really want. The ASRock board is compromise. Do you really want to pay for compromise? Something you might want to ponder. The Opty is a great potential overclocker, why hobble the thing? New vid cards are coming out all the time, so it is better to temporarily compromise there (your AGP card is even a bigger compromise -- depending on the model, of course). Vid cards should be upgraded every two years anyway.

 

[imported_xer0]

From what I have read, the ASRock Dual SATA2 is a great OC'ing board for cheap. There are quite a few topics here that say the same. Check out the mobo section and decide for yourself. Let us know how it goes, good luck!

 

[Navid]

The Asrock motherboard overclocks great up to FSB=274. If you need to go higher than that, you will have to deal with cold boot problems.

 

[JSFLY]

Originally posted by: Zelaya
I've been doing a lot of research for my new setup; basically my question is, if you need to use memory dividers in your overclock of your cpu, by using the divider are you losing out on some overall system performance? If so, how much would I be missing out on?

Overclocking rule #1: MHZ is king. Nothing else matters. If you need to run dividers to get the mhz you need, so be it. Maxing out your mhz will compensate for the dividers.