Bad memory performance of F revision chips fixed!

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02-19-2006, 07:13 AM
Carfax

Bad memory performance of F revision chips fixed!

This news from the Inq may provide a reason for Agenda2005's comment in my other post about Conroe:

Quote:

If you dont know, someone have AMD64 AM2 CPU with DDR2-667 and the conclusion was that infact it run slower than the current 939 CPU with DDR1-400 in many instances, so Intel must have had some way of measuring up the performance of that CPU even by merely overclocking it to DDR2-800 and comparing the performance with Conroe.

I guess the first F revision spin had a bad memory bug which caused memory performance to suck, so this is probably why that "someone" referred to in Agenda2005's post had a lower performing chip than previous revisions.

Anyway, I hope this is true because if it is, it means that the F revision chips will NOT be slower than the E revision :banana:

Even if it does delay them somewhat, I'd rather AMD get it right before they start selling them.
02-19-2006, 07:44 AM
vapb400

Sounds good.

Are Rev F chips going to be on AM2/M2/940 or just socket f/1207?
I'm assuming Rev F is for any DDR2 platform.
02-19-2006, 07:53 AM
Sentential

Quote:

Originally Posted by Carfax

This news from the Inq may provide a reason for Agenda2005's comment in my other post about Conroe:

I guess the first F revision spin had a bad memory bug which caused memory performance to suck, so this is probably why that "someone" referred to in Agenda2005's post had a lower performing chip than previous revisions.

Anyway, I hope this is true because if it is, it means that the F revision chips will NOT be slower than the E revision :banana:

Even if it does delay them somewhat, I'd rather AMD get it right before they start selling them.

What was said above is infact true. However the issue was that the dividers were not being properly applied (instead of 1:1 it would revert the RAM to PC2-3200 not 5300) Memtest showed 2,000MB/S with the RAM at "3200"

(I figured I needed to correct the INQ as they did not explain what the bug was and thus making it appear to be more serious)
02-19-2006, 08:05 AM
turtle

Wow, that is definately news to me. Thanks for the for the info Sentential. All the more reason to wait for Brisbane...Maybe that will be tweaked a little more than just a dummy shrink.

Here I was thinking it would be prepared to do ddr-800+ at cas3 when said chips were ready, and with a good deal of performance increase over cas4 or 5. I guess that isn't the case, or at least wasn't initially.

At least they're working on it and are/did fixing/fix it.
02-19-2006, 08:07 AM
Sentential

Quote:

Originally Posted by turtle

Wow, that is definately news to me. Thanks for the for the info Sentential.

Here I was thinking it would be prepared to do ddr-800 at cas3 when said chips were ready, and with a good deal of performance increase over cas4 or 5. I guess that isn't the case, or at least wasn't initially.

At least they're working on it and are/did fix/fixing it.

Keep a close eye on RAM compatibility. There are alot of RAM related issues on this platform as it stands right now :stick:
02-19-2006, 08:24 AM
vapb400

Thanks for the info Sentential. Memory compatibility is NOT what I want to here.

Conroe is looking more and more attractive IMO.
02-19-2006, 08:37 AM
OmegaMerc

Sounds like they need to drop DDR2 for socket F untill they can adopt the tech without problems.
02-19-2006, 11:47 AM
Carfax

Quote:

Originally Posted by Sentential

What was said above is infact true. However the issue was that the dividers were not being properly applied (instead of 1:1 it would revert the RAM to PC2-3200 not 5300) Memtest showed 2,000MB/S with the RAM at "3200"

(I figured I needed to correct the INQ as they did not explain what the bug was and thus making it appear to be more serious)

So whats the performance like now Sentential?
02-19-2006, 01:43 PM
Cybercat

Quote:

Originally Posted by Sentential

What was said above is infact true. However the issue was that the dividers were not being properly applied (instead of 1:1 it would revert the RAM to PC2-3200 not 5300) Memtest showed 2,000MB/S with the RAM at "3200"

1:1? Suggesting that the actual bus speed of the new A64s is 333? If that's the case, how is it that they're able to deliver even clockspeeds of 2200, 2400, 2600, etc?
02-19-2006, 02:13 PM
agenda2005

Hope things work well for them. Although K8 is not bandwith starved and higher latency DDR2 with increased bandwith is only going to be a mix bag, but lets wait and see.
02-19-2006, 02:48 PM
biohead

Quote:

Originally Posted by agenda2005

Hope things work well for them. Although K8 is not bandwith starved and higher latency DDR2 with increased bandwith is only going to be a mix bag, but lets wait and see.

im with you
02-19-2006, 06:44 PM
nn_step

Actually if you want to get into details.. the 4.3b revision of the memory control has a 15.8% performance edge over s939..
02-19-2006, 06:53 PM
Carfax

Quote:

Originally Posted by nn_step

Actually if you want to get into details.. the 4.3b revision of the memory control has a 15.8% performance edge over s939..

Where did you hear this? Name your source, or state whether you have insider information...

A 16% increase in performance for a memory controller rev sounds a bit fishy!
02-19-2006, 07:36 PM
[XC] Lead Head

Its not 16. 15.8, theres a difference :p:
02-19-2006, 07:38 PM
nn_step

a huge difference if you are really into the benchmarks...:p:
02-19-2006, 07:44 PM
Sentential

Quote:

Originally Posted by Carfax

So whats the performance like now Sentential?

Not exactally sure but as far as I know the divider issue has been fixed. There's no doubt in my mind that AM2 will be signficantally faster than S939, its just a question of by how much.

Quote:

Originally Posted by Cybercat

1:1? Suggesting that the actual bus speed of the new A64s is 333? If that's the case, how is it that they're able to deliver even clockspeeds of 2200, 2400, 2600, etc?

Ive said that it was 333 from the start. The clock speeds listed on various websites are simply incorrect as they are not even numbers.

Honestally tho ive got every confidence that this will all come out ok in the long run, hell its still very very early for any production chip.

Im more impressed that they even decided to go with a 333HTT bus as Intel is only going to use 266 with Conroe. AM2 should have no problem keeping the crown but its gonna be harder on 90nm than it will on 65nm. Certianly wont be seeing as high as 500HTT 1:1 on conroe lol so that will certianly help things along.

Frankly for most A64 owners none of this should be a suprise as most of them are common issues on S939 platforms
02-20-2006, 03:55 PM
Revv23

cool, thanks for the info sentinel, inq made this sound like something that would cause huge delay's, and now it doesnt seem like so much to worry about.
02-20-2006, 04:05 PM
Pinnacle

Quote:

Originally Posted by nn_step

Actually if you want to get into details.. the 4.3b revision of the memory control has a 15.8% performance edge over s939..

Where are you getting this from?
02-20-2006, 04:08 PM
DeltZ

if these kinda performance gains from new mem controller are true

AMD>conroe?

Even if conroe DOES have than 20% increase in performance based on just CPU itself. Gonna be hard to keep up with something which gets 15.8% off a new MC revision.

is that figure theoretical or practical, got any more specific details?

Then added the fact that when it goes 65 nm next year or whenever.. +10/15% efficiency.

Are there any major improves after conroe by the time scale that when AM2 goes 65nm?
Or are intel just gonna have to get sick clock speeds?
02-20-2006, 05:14 PM
krille

Guys, I think nn_step is talking about their DDR3 MC. Because, you still believe M2 will be DDR3, don't you nn_step? And in that case, DDR3 could very well provide 15.8% performance boost (if not more). However, most seem to think DDR3 won't be until early 2007. Is this correct? Please, speak out!

edit: Or were you discussing quad channel DDR2 for socket F (LGA1207) nn_step?
02-20-2006, 05:27 PM
nn_step

I will not speak of the Specs but I will say the Latencies in the revised edition are far better than expected and that the clock speed is a multible of 200..
that is practical application improvement..
02-20-2006, 05:27 PM
dinos22

Quote:

Originally Posted by krille

Guys, I think nn_step is talking about their DDR3 MC. Because, you still believe M2 will be DDR3, don't you nn_step? And in that case, DDR3 could very well provide 15.8% performance boost (if not more). However, most seem to think DDR3 won't be until early 2007. Is this correct? Please, speak out!

edit: Or were you discussing quad channel DDR2 for socket F (LGA1207) nn_step?

:hehe:
02-20-2006, 05:30 PM
nn_step

I am speaking of Revision F Memory controller revision 4.3b.. how is that too confusing for everyone?
02-20-2006, 05:50 PM
krille

Quote:

Originally Posted by nn_step

I am speaking of Revision F Memory controller revision 4.3b.. how is that too confusing for everyone?

OMG!! sorry, i thought you meant 4.3c :stick:
02-20-2006, 05:51 PM
nn_step

Quote:

Originally Posted by krille

OMG!! sorry, i thought you meant 4.3c :stick:

you know full well that 4.3c wont be ready for another 2 months:stick:

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