Was AMD holding back on their fusion line?

[desura]

in the pc space, their fusion chips I find to be highly fascinating, but ultimately not really competitive vs a traditional intel cpu + discrete GPU.

Yet they power the two big consoles of the next-gen.

Was AMD holding back all this while on their APU line, to differentiate the market? Or does this mean that performance for those next-gen will ultimately be disappointing?

 

[VirtualLarry]

I would love to see a consumer version of the PS4 APU, complete with GDDR5 used for system RAM. I think it would kick ass, relatively speaking. But Sony probably wouldn't let that happen.

It would indeed be interesting, if AMD made an 8-core small-core APU for the desktop space, and added enough GPU CUs to make it comparable to console APUs for gaming purposes.

 

[Yuriman]

I don't think anyone really wants to run Windows on Kabini. It's not a stretch to call it a tablet CPU (somewhere between Atom and a Celeron), and many PC games don't scale well to 6/8 threads.

 

[Tuna-Fish]

The reason the fusion chips are so anemic on PC is that their GPUs are basically hard capped by the available memory buses. AMD could easily make one with twice the GPU resources than the current ones, but since the current ones already have much more computational resources than optimal for their memory buses, they would not really be all that much better.

This is why on various hardware fora any rumors about GDDR5, DDR4, stacked memory, or other relevant memory interface technologies being spoken about in relation to APUs raise a lot of interest. If AMD got a better memory interface to use with laptop APUs, their chips would get much better. However, there are unfortunately good reasons why they tend to stay just that -- rumors.

(Mostly that their implementation would require significant risky investment not just from AMD, but many other parts of the stack too, and given the economy and market conditions, no-one is willing to stick their neck out.)

 

[ShintaiDK]

PC buyers dont want a great GPU with an anemic CPU that can barely do regular tasks. Its completely different.

Consoles already suffer from the poor CPU and many games are 30 FPS capped.

AMD is not holding anything back, they are simply limited by their resources, avaliable technologies and declining volume.

 

[Insert_Nickname]

It would indeed be interesting, if AMD made an 8-core small-core APU for the desktop space, and added enough GPU CUs to make it comparable to console APUs for gaming purposes.

I'd like to see an FM2+ Kabini variant with the four CPU cores at 2.5GHz-3GHz, 256 shaders (4CUs) and a dual-channel memory controller. It'd be just perfect for a cheap daily use SFF APU...

 

[NTMBK]

On a console developers have to develop for a fixed platform- if they are stuck with 8 relatively weak threads, then they will write appropriate software. PC games often rely heavily on single threaded performance, so the PS4 APU would not do so well.

However, I would like to see an APU which combined a PS4-quality GPU with 4 Steamroller/Excavator cores and sufficient memory bandwidth (GDDR5? Quad channel DDR4?).

 

[ShintaiDK]

I'd like to see an FM2+ Kabini variant with the four CPU cores at 2.5GHz-3GHz, 256 shaders (4CUs) and a dual-channel memory controller. It'd be just perfect for a cheap daily use SFF APU...

Buy Kaveri then. Kabini becomes useless in that area. If its even possible to clock it that high, not considering a huge TDP increase.

 

[ShintaiDK]

On a console developers have to develop for a fixed platform- if they are stuck with 8 relatively weak threads, then they will write appropriate software. PC games often rely heavily on single threaded performance, so the PS4 APU would not do so well.

However, I would like to see an APU which combined a PS4-quality GPU with 4 Steamroller/Excavator cores and sufficient memory bandwidth (GDDR5? Quad channel DDR4?).

Quadchannel would make the platform very expensive and increase pincount. And soldered on memory is very hard to sell for a CPU. AMD already had to drasticly increase prices of Kaveri. For a product that doesnt really sell. And then you want a much more costly product with a much smaller segment to sell in?

 

[NTMBK]

Quadchannel would make the platform very expensive and increase pincount. And soldered on memory is very hard to sell for a CPU. AMD already had to drasticly increase prices of Kaveri. For a product that doesnt really sell. And then you want a much more costly product with a much smaller segment to sell in?

Oh I doubt it would be a very successful product, I just want one for myself because I think it would be cool

 

[desura]

Well, is there a reason why the desktop APU is hobbled by memory bandwidth issues, while the consoles are not?

 

[ShintaiDK]

Well, is there a reason why the desktop APU is hobbled by memory bandwidth issues, while the consoles are not?

Price.

 

[AtenRa]

but ultimately not really competitive vs a traditional intel cpu + discrete GPU.

In order to have almost the same CPU and iGPU performance of Kaveri A10-7850K, you will need an Intel Core i3 + a GT630.

A10-7850K = $185
TEAM 2x 4GB DDR-3 2133MHz CL10 = $73

Total = $258

Intel Core i3 4330 = $140
Cheapest 2x 4GB memory = $60
EVGA GT 630 DDR-3 (same card used in the review bellow) = $64

Total = $260

http://www.pcper.com/news/Graphics-...mes-A10-7850K-vs-Intel-Core-i3-GeForce-GT-630

You can go with the Core i3 4130 and save a $15 but you will loose CPU performance.

You get higher Graphics performance and the ability to use a Slim mini-itx case with the A10-7850K plus you can OC both the CPU and iGPU.
With the Core i3 you get higher CPU performance and perhaps lower power consumption but you cannot OC and you will need to buy a bigger case.

I will say that Kaveri is competitive with current Haswell parts, but it all depends on your usage and what you are looking to get from you system.

 

[AtenRa]

Well, is there a reason why the desktop APU is hobbled by memory bandwidth issues, while the consoles are not?

Most probably AMD doesnt want to cannibalize its dGPU sales.

If they wanted they easily could add 1GB of GDDR-5 with side-port in selected motherboards.

 

[raghu78]

Well, is there a reason why the desktop APU is hobbled by memory bandwidth issues, while the consoles are not?

The consoles are dedicated gaming devices with a much more customized architecture. For instance Sony chose to go with a 256 bit GDDR5 controller while Microsoft chose to go with 32 MB ESRAM and 256 bit DDR3 memory controller.

AMD's desktop APUs did not have a good solution until now. GDDR5 was high power / high bandwidth and DDR3 was low power / low bandwith. Only now does HBM solve both bandwidth and power concerns. Here is a keynote by AMD Sr Fellow and 3D stacking (HBM) program manager, Bryan Black.

http://www.microarch.org/micro46/files/keynote1.pdf
http://electroiq.com/blog/2013/12/amd-and-hynix-announce-joint-development-of-hbm-memory-stacks/

HBM is the future for all SOCs. 2.5D and 3D stacked DRAM with low power and massive bandwidth. In space constrained form factors like phones, 3D stacking would be the ideal solution. For notebooks, desktops and tablets a 2.5D solution on a silicon interposer would be the best. AMD is likely to make the transition to HBM for GPUs and APUs in their next gen products which should be available in early 2015. The entry level dGPU market below USD 100 has another 2 years before it starts to fade away. the only reason for the AMD APUs to not match the entry level dGPUs is the low bandwidth.

AMD can easily pack 768 sp at TSMC 20nm on their high end APUs. But without adding bandwidth it would wasting silicon area and power. Here is a HD 7750 GDDR5 vs HD 7750 DDR3 comparison. the GDDR5 version is on avg 65% faster than the DDR3 version and in demanding games like BF3,Crysis 2 the perf is anywhere between 1.75x -2x of the DDR3 version.

http://www.hardware.fr/focus/76/amd-radeon-hd-7750-ddr3-test-cape-verde-etouffe.html

a single HBM stack at 800 Mhz provides 102.4 Gb/s bandwidth which is more than enough to power 768 sp without bottlenecks. that APU would perform better than the Xbox One APU.

 

[Erenhardt]

Ohh noes... everything below 7870 will soon be igp.
What is the reason for 7770 graphics card when it can be integrated into CPU.
a10-7850k with HBM would be as fast as 7750 GDDR5.
Will mainstream gaming shift from dgpu to apu?

Can possibly new FM2+ APU have HBM, or is new platform required?

 

[Erenhardt]

a single HBM stack at 800 Mhz provides 102.4 Gb/s bandwidth which is more than enough to power 768 sp without bottlenecks. that APU would perform better than the Xbox One APU.

Shame on Sony and MS. Nintendo go for it! Would be fun to have Nintendo be the fastest console this generation!

 

[Soulkeeper]

Price.

my thoughts exactly.
AMD has the technology and minds to create just about anything, and even win ... but at what cost. I'm sure they could make a massive APU/CPU die with tons of cores and memory lanes. Or throw in newer tech like HBM ddr4 etc.
It's just a matter of return on investment and cost per unit.

In my mind enthusiasts/highend users are being ignored by them, untill the $$ numbers add up (hopefully).

 

[Insert_Nickname]

Buy Kaveri then. Kabini becomes useless in that area. If its even possible to clock it that high, not considering a huge TDP increase.

I'd be nice to have a low power 25-35W option for FM2+, the lowest TDP is currently 45W. 4 "fast" Jaguar cores and mid-tier Trinity graphics performance is not "useless". Throw in a HEVC decoder and you have a potential killer HTPC chip...

Edit; typo...

 

[BSim500]

Was AMD holding back all this while on their APU line, to differentiate the market? Or does this mean that performance for those next-gen will ultimately be disappointing?

I'd have to say the latter. Those 8x tablet CPU's @ 2GHz combined barely match a Haswell i3-4330 and that's in benchmarks with 100% core loading on all 8 cores (which rarely happens in games in reality). Only 6 of those cores are used for games (and it turns out consoles are clocked lower at 1.6-1.75Ghz), so that doesn't help either. That's why as others have said, even in year 1 of release console games are already being capped at 720p & 30fps (and even both!). I haven't played a PC game at under 1280x1024 @ 30fps since, what the 1990's?... In the past, consoles typically aimed at the high-end PC equivalent for launch, but for CPU + GFX, the "next gen" consoles are basically a fast i3 / very slow i5 + a 7790 / 7850 GFX card, which is the first time in many years a console has been barely "mid-range gamer" PC equivalent at launch.

In order to have almost the same CPU and iGPU performance of Kaveri A10-7850K, you will need an Intel Core i3 + a GT630. You can go with the Core i3 4130 and save a $15 but you will loose CPU performance.

Problem is for only $10-20 more, you could get an i3-4130 + GT640 / R7 250, at which point you're suddenly gaining +40-70% higher min & avg fps over the A10-7850K / GT630 level of performance:-
http://www.hardwareheaven.com/revie...-esports-performance-review-introduction.html

This is the problem with "premium" high-end APU's, the pricing of the A10-7850K just doesn't make any sense. It's exceptionally poor value for money for what a huge jump literally $10-20 more can buy with a budget discrete card with its own DDR5 VRAM.

 

[raghu78]

Shame on Sony and MS. Nintendo go for it! Would be fun to have Nintendo be the fastest console this generation!

Sorry but you don't understand. Sony's PS4 GPU has 1152 GCN shaders running at 800 mhz connected to a 256 bit GDDR5 memory bus at 5.5 Ghz (176 Gb/s). Sony's design is similar to mid - high end GPUs, though it draws more power. MS Xbox One design is lower power and a bit more complicated. Xbox One requires more developer effort to extract the best performance and still its inferior to Sony PS4 in performance.

 

[frozentundra123456]

A close to the metal console designed specifically for gaming is a very different animal than a general purpose PC apu. In a console where power and space are limited, an apu was the ideal solution. In a PC however, the more wide ranging applications and the ability to add a discrete card make amd's apus a more problematic solution. And if the 750Ti is any indication, the new generation of gpus is going to make the apu strategy even more difficult by vastly increasing performance per watt for a dgpu.

As for "holding back", it doesn't make sense to me that a company with what, around 25% of the market would be holding back.

 

[mrmt]

in the pc space, their fusion chips I find to be highly fascinating, but ultimately not really competitive vs a traditional intel cpu + discrete GPU.

Yet they power the two big consoles of the next-gen.

The life cycle of a PC SKU is about two years for AMD (launch + simple re spin for AMD, like Trinity and Richland), and they are trying to move their small core line to a yearly cadence, so whatever the R&D money they spent they must recover it in this short time frame.The consoles on the other hand, are warranted to get orders until 7 years down the road, maybe even more, so AMD can spread the investment recover for a lot longer.

Another factor is the supply chain. Sony doesn't need to make money on the PS4, they need to cover the costs. The equivalent of Sony in the PC supply chain are the OEMs, and they *need* to make money on each PC they sell, so they should have higher margins on a PC than Sony in a PS4. Don't forget to add to that higher price the top notch cooling, higher end MB, GDDR5 memory and everything else this super APU would need.

The result of this is that AMD can swallow a 10% margins on console but can't the sub-40% margin of the Bulldozer line, so if AMD were to launch a console APU on the PC market, it would be far more expensive than their current chips, and that for a chip that would perform poorly in most workload outside games extremely optimized for it.

Just to put things in perspective, AMD ASP before APU was below $40, and the console APU themselves, which are slightly above the $100 mark. That APU would have a ASP at AMD's door of at least $150 if AMD were to recoup their money. I can't fathom this processor costing less than $300 + taxes + the more expensive platform, best case, to the end user.

In the end, I don't think there's a solid business case here.

 

[Shaydza]

I wonder what kind of performance boost would be achieved by tri channel memory vs the current dual channel architecture currently used. Correct me if I am wrong but wouldn't that lift memory bandwidth by 50% and seriously help apu performance without having to adopt a new memory type.

 

[shady28]

Some have mentioned this already, but GDDR5 can make a huge difference in performance on an APU.


http://www.gaminglaptopsjunky.com/gt-750m-gddr5-vs-gt-750m-ddr3-gaming-performance-tested/

Chart below - we're talking 15fs vs 27fps, 16fps vs 23fps, 25fps vs 40fps, and 17fps vs 25fps. This is for discrete DDR3 vs GDDR5.

Basically the "APU" on the PS4 is going to perform quite a bit better than what we see on DDR3 desktop/laptop systems.

My guess is we won't see the kind of GPU performance that PS4 puts out on a PC APU for at least 2 more generations, and probably not until we see DDR4 based PCs (which might mess up the price/performance aspect of an APU).


Model GT 750M DDR3 (FPS) GT 750M GDDR5 (FPS) GT 750M GDDR5, MEM@1500MHZ (FPS) GT 750M DDR3, MEM@1080MHZ (FPS)
Skyrim, highest settings@1080p 15 27 22 17
Bioshock, highest@1080p 16 23 22 18
Borderlands 2, highest@1080p 23-25 40 32 25-26
Tomb Raider 2013, ‘ultra’ settings@1080p 17 25 22 20.5