AMD Zambezi news, info, fans !

[bamtan2]

debating cores and modules etc nomenclature is nonsense imo. its imaginary. all the OS and the apps see are THREADS! that is where the rubber meets the road.

[jabway]

From a technical point of view it makes no difference, but what do you think the average consumer thinks? If an "8 core" cpu performs like/worse than the competitor's 4c/8t cpu it doesn't look as good.

[Manicdan]

From a technical point of view it makes no difference, but what do you think the average consumer thinks? If an "8 core" cpu performs like/worse than the competitor's 4c/8t cpu it doesn't look as good.

so they market it as buying more cores for less
very few people actually know performance, most have learned ghz, and a few have learned cores, id be willing to be less than 1/20 know performance if you give them 2 popular chips to compare.

[Leeghoofd]

Even with 4 cores all CPUs are more than suitable enough for gaming etc...

An average consumer hardly knows anything about how it performs. They just see 3.6Ghz, turbo 4.2 and they are partly sold...

[radaja]

Even with 4 cores all CPUs are more than suitable enough for gaming etc...

An average consumer hardly knows anything about how it performs. They just see 3.6Ghz, turbo 4.2 and they are partly sold...

yep the average consumer really has hit a plateau when it comes to performance they can really gauge,it really hasn't made one bit of a difference since nehalem and phenom II came out.again to the average consumer.IMO

[zalbard]

Even with 4 cores all CPUs are more than suitable enough for gaming etc...

An average consumer hardly knows anything about how it performs. They just see 3.6Ghz, turbo 4.2 and they are partly sold...

"Turbo 4.2" is too complicated already.

[informal]

For the record, and another reference. going back to my Bobcat clock/clock comparisons
Per core K10 is:

Super pi 5% faster
Fritz chess: K10 20% faster
Cinebench 11.5: 49% faster

at the same clk speed.

which means, somehow Bulldozer is about the same performance :S , even on some of these SSE/FPU heavy benches.

Has anyone determined the pipeline length details for Bulldozer? I believe Bobcat is 15 stages vs 12 for K10

It is likely a bit longer to enable these high clockspeeds, but I'm still finding some of the results out of line. I know you didn't look up superpi, but it for one is, according to these results slower than Bobcat (as i've mentioned before), given the architectures seem to be similar, I find this quite odd.

Even if the pipeline stages are longer than Bobcat's the massive amounts of Cache, much larger buffers, much wider more capable performance orientated FPU (Bobcat has a very trimmed down FPU due to its target market) , assumed more aggressive prefteching It certainly doesn't make much sense at this stage.

I can understand similar IPC to Thurban given the higher frequency headroom, and trade-off's to achieve high performance / watt (all valid design decsisions), but these outlier results like Cinebench, Wprime, Fritz, are quite baffling

I agree with you. I personally think something went horribly wrong between the Q4 of 2010 and Q2 of 2011 and now instead of a chip which has a thread count of 8 ,whose each "thread" is at least as strong as Thuban's core in MT and at least 10% stronger in ST workloads(both int and fp),we end up with a Bobcat level of performance per core,roughly of course, which can clock really high though ,but which scales poorly (1.7x or 1.8x over single thread). Even little bobcat ens up faster in select few benchmarks (per clock). To release this thing as a successor to relatively successful Phenom II line is very much crazy.
I'm especially baffled by really slow FP unit. Bobcat's FPU looks like to be on a similar perf. level (per "thread") as Bulldozer's. Sounds crazy but it's true. Just forget K10.

That's why I think this is not final performance. Because why would AMD release something that's worse than what they had before? They'd have to be bat sheet insane to do that.

I have no idea to be honest. Maybe they didn't expect to see this from their simulations? This thing was supposed to be a Thuban crushing machine,excelling at MT workloads and being 30-50% faster at the same TDP as per John Taylor. This is the post I wrote on AT forum few days ago:

This video is from March 8 this year. It was shot at Cebit 2011. It features Macci and John Taylor @ AMD. Mr Taylor said @ 2:20 mark that bulldzoer was designed to deliver 30 to 50% more performance within the same TDP envelope and roughly the same die are versus the cpu it replaces. The video is here.

What I want to know now is in which real world or synthetic benchmarks/workloads is Zambezi going to deliver 30-50% more performance than Thuban and with which magic dust is this going to happen? With the latest numbers it barely beats Thuban in highly MT workloads like cinebench(both old 10 and new 11.5) and handbrake. The difference ranges from tiny to 10 or so %. This is 8T vs 6C case,so best case scenario for Bulldozer. Bulldozer even runs at much higher clocks (both stock and Turbo). Where is 30% difference (just forget 50%)? Oh yes,AES and such are just outliers so those are corner cases.

If it was supposedly designed to deliver 30-50% more performance and if Mr Taylor stated this in the context of very parallel workloads (which is legitimate ) then we can say Bulldozer failed since it can't overall outperform Thuban by more than 20%,let alone 30% or now astronomical 50%. In order to achieve this ,the Bulldozer that John Taylor talked about must be the same one from this slide (and no,this slide was not fake). What happened in the meantime ? How from this 30-50% throughput machine we ended up with barely faster than Thuban? Unless the Bulldozer John Taylor spoke about in the video was expected to run at 4.5-5Ghz stock clock and Turbo to 5.5Ghz ,all within 125W TDP envelope,then something else went wrong and now we get "this" (slower than Thuban at the same clock by 5-15%,depending on the app and barely beating it since it has weaker core scaling and only 1.33x more cores to make up the difference).

[Apokalipse]

I have no idea to be honest. Maybe they didn't expect to see this from their simulations?

Let's say it did fail to meet expectations and actually is worse than K10.5, it would make no sense at all to actually release it. AMD would cancel the release and work on getting something out that actually is better.

The fact that they are releasing it means it will be better than K10.5. Either that or the management have no sense of reality at all.
Without benchmarks, we won't know how much faster than K10.5 it is, or whether it beats SB in IPC and/or single threaded performance; all we can know is it will be faster than K10.5.

If not, then the entire management at AMD should be given a visit by the nice men in white coats.

[informal]

Let's say it did fail to meet expectations and actually is worse than K10.5, it would make no sense at all to actually release it. AMD would cancel the release and work on getting something out that actually is better.

The fact that they are releasing it means it will be better than K10.5. Either that or the management have no sense of reality at all.
Without benchmarks, we won't know how much faster than K10.5 it is, or whether it beats SB in IPC and/or single threaded performance; all we can know is it will be faster than K10.5.

If not, then the entire management at AMD should be given a visit by the nice men in white coats.

In well MTed applications it will be faster than X6 1100T,but this will happen only with 8150 running 3.6Ghz+ Turbo. It will be faster by some 5 to 20% max . In ST workloads or poorly threaded ones(1-4 threads),even with it's max. Turbo it won't beat Thuban ( at 3.7Ghz which is max Turbo for it).

[Apokalipse]

In well MTed applications it will be faster than X6 1100T,but this will happen only with 8150 running 3.6Ghz+ Turbo. It will be faster by some 5 to 20% max . In ST workloads or poorly threaded ones(1-4 threads),even with it's max. Turbo it won't beat Thuban ( at 3.7Ghz which is max Turbo for it).

I think you put far too much stock in the idea of leaked performance being an accurate representation of retail.

[informal]

Yes I did,it matches the press kit pretty well. 8150 was depicted as being between 2500K and 2600K performance wise,all in mostly well MTed workloads. 1100T already occupies that performance region as it is mostly faster than 2500K in well MTed applications .

[Apokalipse]

Yes I did,it matches the press kit pretty well. 8150 was depicted as being between 2500K and 2600K performance wise,all in mostly well MTed workloads. 1100T already occupies that performance region as it is mostly waster than 2500K in well MTed applications .

1100T is the same price as a 2500K, and is slower in single threaded tasks.
If the FX was even slower in single threaded tasks than 1100T, they'd be utterly retarded to release it especially at a higher cost.

[Manicdan]

think the "flex" fp is the main cause? or is the int perf just as bad?

[Apokalipse]

think the "flex" fp is the main cause? or is the int perf just as bad?

Most instructions used by real (as opposed to synthetic) programs are integer instructions. But I think the low performance is not specific to integer or FP.

It could be something simple like new microcode enabling certain features, we'll have to wait and see.

[MaddMutt]

Let's say it did fail to meet expectations and actually is worse than K10.5, it would make no sense at all to actually release it. AMD would cancel the release and work on getting something out that actually is better.

The fact that they are releasing it means it will be better than K10.5. Either that or the management have no sense of reality at all.
Without benchmarks, we won't know how much faster than K10.5 it is, or whether it beats SB in IPC and/or single threaded performance; all we can know is it will be faster than K10.5.

If not, then the entire management at AMD should be given a visit by the nice men in white coats.

Are you implying that there might still be a revision out there??????

From earlier post's on here, it was implied that Bulldozer is final with stepping B2 and they received it on the 5th of this month??????

Both JF and Movieman have stated that the early ES samples had problems and that WE would see the REAL PERFORMANCE when it was finished and shipped.

I don't think CHEW ( also posted on here) who set a World Record with the BD (WTG), would have told us that the ES samples were bad and don't believe the bad numbers from them.

Some of you Xtreme Members might have the shipping BD ver in hand and running the Benchmarks right now!!!!!!!

This is all speculation as the NDA will probably not be lifted until BD is on store shelves

[Apokalipse]

Are you implying that there might still be a revision out there??????

microcode is contained in BIOS. All AMD would have to do is release a new AGESA version and let manufacturers put it in a new BIOS.

This is all speculation as the NDA will probably not be lifted until BD is on store shelves

We have some information, but exact performance is speculation.

I'd say we can expect them to be faster than K10.5; I don't know if we can make any more expectations than that though.
It could have faster single threaded performance than SB, or it could be slower. I would guess it would be about in the ballpark; but I don't really know.

[Oese]

I think you put far too much stock in the idea of leaked performance being an accurate representation of retail.

thing is, ALL leaks look like this. Also what leeghoofd indicates.. or he is following the nda in a way that says explizitly "post fake sub-par performance numbers (that are included in the kit, originally taken from a formerly famous, legid reviewer, that was now paid by AMD to loose all his reputation and now is AMD's no.1 paid fud spreader) to let all ppl think bd is flawed and then post real results on launch day claiming u got a bios update on last day before launch"

[Apokalipse]

thing is, ALL leaks look like this.

Yeah, and I think they did with K6 -> K7 too.

[MaddMutt]

microcode is contained in BIOS. All AMD would have to do is release a new AGESA version and let manufacturers put it in a new BIOS.

Thank you for the correction.


I was hoping that there was some other reason for the bad numbers

If AMD thinks they can get better numbers with higher speed Is this not what Intel tried to do with the P4/Netburst??????

[Oese]

Yeah, and I think they did with K6 -> K7 too.

i'd like this to happen ofc^^

btw, the people that were given away bulldozers at the event today also signed nda?

@Matt: Problem those times was the frontend, and the long pipeline was calculating irrelevant things due to wrong brach prediction. That took much power and yielded bad output...

BD has prefetcher and OoO execution, and not that long of a pipeline..

[Apokalipse]

i'd like this to happen ofc^^

btw, the people that were given away bulldozers at the event today also signed nda?

I'd say it would be conditional to them receiving a BD chip.

[radaja]

thing is, ALL leaks look like this. Also what leeghoofd indicates.. or he is following the nda in a way that says explizitly "post fake sub-par performance numbers (that are included in the kit, originally taken from a formerly famous, legid reviewer, that was now paid by AMD to loose all his reputation and now is AMD's no.1 paid fud spreader) to let all ppl think bd is flawed and then post real results on launch day claiming u got a bios update on last day before launch"

yea i agree,i find it hard to believe that amd is behind the FUD and that a new bios will make a big impact with ST performance and save the day.
i think it is more likely that frequency will be the thing that puts it above thuban and compete with SB.but thats just my opinion

[Apokalipse]

yea i agree,i find it hard to believe that amd is behind the FUD and that a new bios will make a big impact with ST performance and save the day.
i think it is more likely that frequency will be the thing that puts it above thuban and compete with SB.but thats just my opinion

With all the work and details added to the architecture, I find it hard to believe it's even possible for it to have lower IPC than K10.5.

I don't know if a new microcode will make it faster; it seems a likely possibility though. But I do think AMD is probably holding something back.
And whether it's faster than SB or not (single threaded), it at least keeps Intel in the dark.

In any case, I don't think AMD wants to spread FUD about bad performance. They want it to be unknown, to keep Intel in the dark.

[MaddMutt]

Most instructions used by real (as opposed to synthetic) programs are integer instructions. But I think the low performance is not specific to integer or FP.

It could be something simple like new microcode enabling certain features, we'll have to wait and see.

Question on the microcode????

Does AMD write the code and then give it to the Mobo makers, or do the Mobo makers also put something in there?????

[Apokalipse]

Question on the microcode????

Does AMD write the code and then give it to the Mobo makers, or do the Mobo makers also put something in there?????

I'm pretty sure AMD releases a binary containing the AGESA code that motherboard manufacturers include in their BIOS.

With some BIOS's, you can actually extract or replace the AGESA binary yourself (although I wouldn't necessarily recomend trying). But people have been able to modify their BIOS to support newer CPU's this way when the manufacturer decided not to release any new BIOS themselves.