AM2 Overclocking

[kellamne]

Q.

Will there be much difference in method for Oc'ing an AM2 - from that of the 939? Wondering whether DDR2 changed the method much or at all - and if so - what the new method is.

[SteveI]

It should be good... DDR2 is offered at much higher speeds than DDR could hope for, albeit with very high latency.

For synchronous work, AM2 should be a boost, and the newer mobo chipset should handle higher clock frequencies well.

[Seperah]

I'm wondering if we'll be seeing a Crossfire 3200 board supporting AM2 soon...

[cadaveca]

Bandwidth offered by AM2 is astounding...unbuffered AM2(10k-11k) SiSoft SAndra benches look like buffered 939 (6k-7k)benches. Should make overclocking a bit more difficult on the ram itself.

[dsio]

This is true, but might we be seeing some low latencey DDR2 chips available once demand for them is created by AM2? Overclocking them clearly isn't going to net much in the way of performance gains, as overkill+1 is still overkill, but if they are able to drag DDR2 latencey down towards CAS2 again, there may be some nice little improvements.

[cloasters]

It's possible that the increased latency of DDR2 isn't much of a performance hit. Read this somewhere.

[madcatmk3]

They have CL3 DDR2. Anyway I'm build an orleans 3500+ for someone, to bad I'm not going to overclock it much as it's on a biostar board unless the Epox releases for around $80.

[cadaveca]

DDR2 on AMD has nowhere near the performance loss going form DDR1 that the P4 suffered when it made the move. Benefits of an on-die memory controller...so there is no real need for lower latency ram for AM2. I'd love to see a p4 get 11k buffered.

It's this high bandwidth that makes it harder to clock ram under AM2...ram is getting used far more intensely than the P4 ever could @ 800mhz. i mean really...11000mb/sec? do we REALLY need that much?


Not for a single or dual core.....

[madcatmk3]

Ya AM2 with DDR2 will probly kick ass compared to 939. But are you saying when we OC them we'll have to keep the ram closer to the original value? Anyway how do BIOSTAR board OC? and how many USB ports does the AM2 epox board have?

[wolverineI]

had my m7ncd running at 225x10 with a barton 2500,heard the new
am2 has better options than normal for biostar.very stable mobo
sold mine to a friend after his brand new case and psu took out the gigayte pro he had.mine ran 24/7 as my work comp for 2 years before
selling it to him,hes very happy with the upgrade from p3 500mhz.

[dsio]

Originally Posted by wolverineI

had my m7ncd running at 225x10 with a barton 2500,heard the new
am2 has better options than normal for biostar.very stable mobo
sold mine to a friend after his brand new case and psu took out the gigayte pro he had.mine ran 24/7 as my work comp for 2 years before
selling it to him,hes very happy with the upgrade from p3 500mhz.

Upgrading from a P3 500Mhz must have been mind blowing.

I remember how good I felt when I went from my 486DX2 to a K6-2. We never get to enjoy those massive gains these days

[Allan]

Originally Posted by madcatmk3

Ya AM2 with DDR2 will probly kick ass compared to 939.

Actually, no. AM2 with DDR2-800 is 1-2% faster overall than a s939 setup with the same CPU type. That isn't exactly kicking ass. I'm currently testing a setup with an AM2 X2 5000+.

Btw, you should consider staying clear of the odd multiplier versions of the AM2 (4200+, 4400+ and 5000+) since these cannot run DDR2 at 800. Because of the odd multiplier, and lack of "half" memory multipliers, they will run the DDR2 at 742 MHz instead of 800 MHz.

[SteveI]

Originally Posted by Allan

...
Btw, you should consider staying clear of the odd multiplier versions of the AM2 (4200+, 4400+ and 5000+) since these cannot run DDR2 at 800. Because of the odd multiplier, and lack of "half" memory multipliers, they will run the DDR2 at 742 MHz instead of 800 MHz.

Very interesting point Allan. I'll have to do some digging. I am going to do some serious upgrading this summer, but I'm leaning toward conroes. I want duallies.... and bang for the buck, I think Intel may be the better value. However, I want a complete picture. High memory bandwidth is never a bad thing, but it seems there is an artificially high number of models out there.

Can you translate "odd" for me?

[Allan]

Originally Posted by SteveI

Very interesting point Allan. I'll have to do some digging. I am going to do some serious upgrading this summer, but I'm leaning toward conroes. I want duallies.... and bang for the buck, I think Intel may be the better value. However, I want a complete picture. High memory bandwidth is never a bad thing, but it seems there is an artificially high number of models out there.

Can you translate "odd" for me?

Odd, as in an odd number, not an even number. For example, the 5000+ has a multi of 13x.

200 FSB * 13 = 2600 MHz for each core.

You need to find a suitable level for the RAM, wanting to hit 400 MHz. This means that:
2600/6 = 433, which is too much.
2600/7 = 371, which is too low. (742 MHz as I mentioned in the first post)

There is no sweet spot hitting 400 MHz, so you will find your RAM running an underclocked speed. Gimme a few days to play with this setup, and I will see how it handles to be overclocked.

[madcatmk3]

sounds fun

[cadaveca]

AM2 cores are currently the same core as on 939...overclocking should fare teh same or better or worse....depends on ram.


Although there is higher bandwidth offered by AM2, this is not a nessecary boost for dual/sinlge core AMD's...it's there for the next step in the AM2 platform.


BRING ON THE QUADCORES!!!!

[cloasters]

It's great to hear from you, Allan! Glad that you're ahead of the crowd!

It's a shame that quad cores, or eight cores for that matter just aren't great for gaming. Do the high end Opterons have to be so utilitarian? Oh well, who could afford them for a gaming rig? I know, don't ask.

[cadaveca]

DX10, cloasters! DX10!! Physics API in DX can use other cores, nevermind sound, etc. Vista should be multi-core friendly. We will ahve to wait a bit for it to be widely adopted before game publishers take full advantage of what is there, but i think the wait will be worth it.

[BobRoss]

Originally Posted by cadaveca

DX10, cloasters! DX10!! Physics API in DX can use other cores, nevermind sound, etc. Vista should be multi-core friendly. We will ahve to wait a bit for it to be widely adopted before game publishers take full advantage of what is there, but i think the wait will be worth it.

Wow!! I am really excited about this!! That could really make a big difference. I do expect that we will need to wail till next year to see the benefits though.

[Favu]

Originally Posted by cadaveca

overclocking should fare teh same or better or worse

Finally the definative answer I've been waiting for!

hehe