What memory for an overclocked s939 3000+

[TiG]

I'm still planning my future system, and i'm yet to find much evidence of many people overclocking a 3000+ AMD64 winchester core.

Therefore i'm not sure whether things like PC4400 memory or PC3200 memory is better?.

I'd like to get a 3000+ system and overclock it from its 9*200 to 9 * 275 if possible, and get memory running in 1:1 ratio with it.

Any ideas links or reviews of something like this being done about??.

TiG

[Rave]

www.xtremesystems.org

From what I can gather, persuading 2x512MB sticks to run at 1:1 with a 1T command rate is tricky at anything over 260FSB. That would still be pretty seriously quick mind you.

Remember that running at '1:1' is not the be all and end all like it is on an Athlon XP system. You could run (say) 8 x 320HTT with the memory set @ PC2700 in bios, that by my calculations would give you a 256MHz memory speed.

Rich :¬)

[TiG]

Hence the question. While there is some info on there, i'm still puzzled over the whole HTT vs Memory/FSB things.....

All i want to know if i get a 3000+ and i overclock it, am i going to be best with buying some PC3200 memory at say £150 or some PC4400 memory at £200?. And if so what overclock am i looking at?.

and what is 8* 320 HTT?, i thought HTT was 1000mhz?

TiG

[Zak33]

glad you asked it...I didnt even know HOW to ask it. Still suprised by the mobo's running PC2700 at all !!

[TiG]

Sadly i think i'm asking a rhetorical question, I'm hoping Rysard sees this as i think he'll be maybe the one of the only people i trust with letting me know this information. When i go this route it will be very much pc4400 memory and then seeing what i can get out of the machine if i'm still not sure what is best

TiG

[Rave]

Well....faster memory certainly helps you get a willywaving Sandra score, like 8GB/s+ buffered. That doesn't really translate to huge gains in most programs/games though, because the A64 isn't particularly bandwidth limited. If you're stumping up serious cash for the system, like SLI or a 6800U, pukka motherboard, RAID etc. then an extra £50 for the RAM to finish it all off is probably reasonable. Get some decent TCCD- based modules in there and get on with it.

I OTOH when I'm able to put together a S939 system will probably just shove in a gig of cheapy PC3200 and put up with the 2-3% performance loss compared to the top end stuff.

As for A64 overclocking, as I understand it it goes like this. The A64 doesn't have a front side bus as such like the P4/ Athlon XP. Instead, it just has a memory controller channel, and an entirely seperate connection to the chipset (the Hypertransport link). So, the frequencies of these links can be varied seperately.

The main clock control is called the HTT (I'm pretty sure) and then the processor's speed runs at a multiplier of this. For a S939 3000+, you can choose anywhere between 4 and 9. The stock HTT is 200MHz, obviously. However, the memory and Hypertransport then run at this frequency, or at a multiplier or a divider of it. The stock Hypertransport speed is 5x200MHz, but you can run at as low as 1X200. 3 X 320 would give you 960; that's actually slower than stock despite the HTT being much higher, but it won't affect the performance.

The memory is the same. Shove some PC3200 into a stock system and it'll run at exactly the HTT speed. Put in some PC2700 though and it'll run at a divider. This should be 5:6 to get it at stock 166MHz speed, but in fact the divider used is 4:5 (I don't know why) this gives a speed of 160MHz. 4/5ths of 320 though would be 256MHz, which is a good speed for top end RAM without going to extreme voltages/ very low timings. So, although the RAM is set at PC2700 in the bios, it's actually running at over PC4000 speed since the HTT has been bumped up by more than 50%.

Hope that clears things up a little?

Rich :¬)

[TiG]

Yep it does Rave, thanks for that. So asynchronous ram isn't an issue as its controlled by the HTT right?.

Hence there is no need for 1:1 mem/cpu relationship.

TiG

[Rave]

Well, the memory controller on the CPU runs at a divider of the HTT. There's basically no such thing as running memory asynchronously on an A64, hence there's no performance penalty.

Rich :¬)

[speedy_s]

Just one more thing
If u get a A64 3200@250HTT you get 2.5Ghz and then if i run the divider 5:6 ram would be 200Mhz right ? Therefore i can get away with cheap ram this time for o/c ing ?Right?

[BUFF]

Just one more thing
If u get a A64 3200@250HTT you get 2.5Ghz and then if i run the divider 5:6 ram would be 200Mhz right ? Therefore i can get away with cheap ram this time for o/c ing ?Right?

208fsb on RAM (useful app. A64 memfreq http://www.forumdeluxx.de/forum/showthread.php?t=82491)
If you are running Dual Channel then the cpu will have more than enough bandwidth.

[speedy_s]

208fsb on RAM (useful app. A64 memfreq http://www.forumdeluxx.de/forum/showthread.php?t=82491)
If you are running Dual Channel then the cpu will have more than enough bandwidth.

sorry i meant 5:4 ratio ! then it would be bang on target !!!!!!!!!!!!!

[Byron]

Memory eh?,
I bought my self 2x512mb PQI memory and runs superb on mine, 288fsb's, prolly can do 290's 1:1 with x8.5 multy... still during testing tho. But deffo recommend it! and the OCZ 3200DDR Platinum REV2 which is basically the same with the PQI's (samsung IC's and same pcb).

[MuzTee]

"i have an msi noe2 plat nf3 and a64 3200+ win 90 nm doing tests i find my max htt is around 284 my max cpu speed is about 2500 ghz but my me maxes out at 220 fsb. i wanted to run 9 x multi plier at 266 htt and 266 1:1 mem. atm i can only go 266 htt and 166mhz mem max giving me 220 fsb mem biottle necking my pc

any suggestions would b much apprecaited

atm i like the look of

OCZ 1GB (2x512MB) PC4400 Dual Channel Gold Series Limited Edition EL-DDR CAS3.0 (MY-031-OC)
but if any one knows better plz tell! "

HEY i asked the same question, but as on my post no one really had a proper answer jus some chitchat about other stuff........

so if someone has the answer please PUT IT here!!!!

i need some memory that will run 280 fsb at 1t 1:1 timing same as this dude. dont need to know that mem can do this that or the other jus please can someone say yes there is memory to run 280 fsm 1t 1:1 or no there isnt.

im not interested in doing 8 x 320 htt etc my system maxes at 285 htt so i wana push my system to its limit and run mem at same speed of htt limet thus getting the most from my system

oh seems like byron already answered soz didnt see the last post, any one know of any others? and byron wot board u got this memory on btw?

[Byron]

MSI Neo2 Platinum with winchester 3200 cpu.
I'm limited too at 286fsb @1T 1:1 (CL2.5 3-3-8) rock stable with 2.6vdimm (from bios) and 8.5x multi... not such a good chip (mine).

Just for the info,some other peeps got better results with same mem and 3500 newcastle though :S

[MuzTee]

where can i get the pqi mem ??

[Byron]

I've send you a pm .