Predict: The Next Generation Console Tech

[Heinrich4]

There is a good discussion here * and im think particularly (IMO big here) that costs of GDDR5 will not reach three times more than a DDR3, yet their price is so low and the facilities of contracts they can get Sony, Nintendo and MS i don't believe that is impossible to have 1 to 2GB or even more GDDR5 on a console.

* http://hardforum.com/showthread.php?t=1595147&page=4

 

[Kaotik]

I thought VLIW4 was GCN?

No, VLIW4 was just VLIW4, not sure if it had even any fancy name like the latest VLIW5's (TeraScale, TeraScale 2)

GCN is completely different architecture, and not VLIW at all. 7900-, 7800- and 7700-series are all GCN

 

[Rangers]

Let's wait and see how it goes, but another IMO, I hope something like a 64MB ( sharing cpu and gpu) eDRAM 512GB/sec almost like L3 cache power7* and no more than 1.5GB RAM (GDDR3 or 1T-SRAM) at 32GB/sec.

*http://www.7-cpu.com/cpu/Power7.html

I dont expect more than 16MB of any type of embedded RAM in Wii U. lherre made some comments as much.

 

[bgassassin]

I dont expect more than 16MB of any type of embedded RAM in Wii U. lherre made some comments as much.

lherre was talking about L2 cache. I know because it was in response to my post. I can confirm that barring any changes the eDRAM will be 32MB.

 

[Rangers]

lherre was talking about L2 cache. I know because it was in response to my post. I can confirm that barring any changes the eDRAM will be 32MB.

Where did you learn that?

 

[bgassassin]

Where did you learn that?

brain_stew first mentioned it, and I was able to confirm it elsewhere.

 

[Rangers]

Quite the interesting factoid if true. It would show EDRAM may still be an essential part of any console going forward, and perhaps give some hints what Microsoft could shoot for in terms of EDRAM (I would assume at least double what Nintendo would do).

That's if true, which I'm a little skeptical.

 

[Shifty Geezer]

lherre was talking about L2 cache. I know because it was in response to my post. I can confirm that barring any changes the eDRAM will be 32MB.

So...16 MBs eDRAM on CPU and 32 MB on GPU?

 

[Entropy]

So...16 MBs eDRAM on CPU and 32 MB on GPU?

eDRAM is unlikely to be used as L2 cache for the CPU. Thus any comment re:L2 can probably be assumed to be unrelated to eDRAM. (Note that Power7 uses eDRAM as L3). Also, 32MB takes up a substantial part of the 567mm2 Power7 die. It's certainly a possible on-CPU amount, but it definitely wouldn't come for free.

32MB - just how did that line up with various buffer needs and configurations?

 

[Teasy]

So...16 MBs eDRAM on CPU and 32 MB on GPU?

The L2 cache is quite a bit less than 16MB, or that's what lherre said anyway.

eDRAM is unlikely to be used as L2 cache for the CPU. Thus any comment re:L2 can probably be assumed to be unrelated to eDRAM. (Note that Power7 uses eDRAM as L3). Also, 32MB takes up a substantial part of the 567mm2 Power7 die. It's certainly a possible on-CPU amount, but it definitely wouldn't come for free.

32MB - just how did that line up with various buffer needs and configurations?

The 32MB is embedded on the GPU not CPU.

 

[Shifty Geezer]

The L2 cache is quite a bit less than 16MB, or that's what lherre said anyway.

Is it supposedly eDRAM though? I don't understand the point of eDRAM for a console cache. It won't need massive amounts like a server processor, and a few MBs is better served with SRAM. 32MB GPU eDRAM makes sense given previous Nintendo designs. I think they'd be happy to run a lot of rendering work out of the eDRAM and have slower RAM.

 

[Teasy]

I'm not sure, I haven't heard much about the CPU cache outside of vague info on amounts. I think the eDRAM thing comes from IBM mentioning it in their press release.

 

[Crossbar]

How much more expensive is GDDR5 compared to ddr3? At my part time job we sell 4gb ddr3 for 20 euro's and this store isn't exactly the cheapest place to buy parts at. I suppose a console builder won't even be paying 10 euro's for 4gb if they buy directly from whoever is producing the memory. If GDDR5 is much more expensive, could we see seperate memory pools again? 1gb GDDR5 and 4gb of ddr3?

At the very bottom of this page you'll find an table with some interesting information of the BOM of AMD grahic cards.

http://www.investorvillage.com/mbth...mValue=216617&dValue=1&tid=10777550&showall=1

1 GB of GDDR5 is about $20, it varies some depending on the speed. I would have loved to see 4 GB of memory in the next gen consoles. But 2 GB is probably the best we can hope for even though the price will drop.

 

[Shifty Geezer]

A quick Google had PS3's BOM for RAM pegged at $50. If going for a high end machine, and not needing to spend as much on drives or CPU this time around, and factoring in a RAM price drop, 4 GBs doesn't look too costly, even if it was nearer $80 costs at launch. It'd also simplify the rest of the system regards memory buses and layout versus split RAM, and make developers' lives a lot easier, so the extra $20 or so it may cost seems good value to me.

 

[Kaotik]

At the very bottom of this page you'll find an table with some interesting information of the BOM of AMD grahic cards.

http://www.investorvillage.com/mbth...mValue=216617&dValue=1&tid=10777550&showall=1

1 GB of GDDR5 is about $20, it varies some depending on the speed. I would have loved to see 4 GB of memory in the next gen consoles. But 2 GB is probably the best we can hope for even though the price will drop.

The problem with RAM isn't the price - it's the fact that you can't go with a lot of mem without a wide bus, and wide bus is what makes things expensive.
2GB is the theoretical max for GDDR5 with 128bit as far as I know (that would already be clamshell mode), and 128bit > 256bit bus would drag the costs up noticeably - not only would the GPU have to be bigger, it would also require a lot more complex PCB design

 

[bgassassin]

Quite the interesting factoid if true. It would show EDRAM may still be an essential part of any console going forward, and perhaps give some hints what Microsoft could shoot for in terms of EDRAM (I would assume at least double what Nintendo would do).

That's if true, which I'm a little skeptical.

LOL. Well if it's true then it's not a factoid. And if you noticed lherre denied that it had 16MB of cache, but did not say anything about the 32MB. But I've seen enough to have an understanding why devs were saying what they had been early one. I've also seen pictures of the dev kit which just added to my belief they are targeting a die shrink for the GPU, whether 32nm or 28nm.

So...16 MBs eDRAM on CPU and 32 MB on GPU?

3MB L2 cache and is split asymmetrically among the cores, 32MB of which I believe will be on an MCM with the GPU like the 1T-SRAM in Wii.

eDRAM is unlikely to be used as L2 cache for the CPU. Thus any comment re:L2 can probably be assumed to be unrelated to eDRAM. (Note that Power7 uses eDRAM as L3). Also, 32MB takes up a substantial part of the 567mm2 Power7 die. It's certainly a possible on-CPU amount, but it definitely wouldn't come for free.

32MB - just how did that line up with various buffer needs and configurations?

Actually the PowerPC A2 uses the same eDRAM for L2 cache. This is how I believe Wii U will achieve 3MB of L2 cache without making the CPU die big.

 

[jonabbey]

The problem with RAM isn't the price - it's the fact that you can't go with a lot of mem without a wide bus, and wide bus is what makes things expensive.

People have been saying that for years, and it certainly looks as though the console developers have been treating a 256bit bus as something strenuously to be avoided.

2GB is the theoretical max for GDDR5 with 128bit as far as I know (that would already be clamshell mode), and 128bit > 256bit bus would drag the costs up noticeably - not only would the GPU have to be bigger, it would also require a lot more complex PCB design

So how much extra cost are we likely to be talking about with a wider bus? As mentioned above with RAM costs, it can't be as expensive as the 405nm laser diodes were for Sony at PS3's launch, or the cost of the hard drive, or the development expense of the CPU and GPU, can it?

Would going with a wide bus prevent them from moving to a narrower bus if more advanced RAM chips come out?

 

[dagamer]

People have been saying that for years, and it certainly looks as though the console developers have been treating a 256bit bus as something strenuously to be avoided.



So how much extra cost are we likely to be talking about with a wider bus? As mentioned above with RAM costs, it can't be as expensive as the 405nm laser diodes were for Sony at PS3's launch, or the cost of the hard drive, or the development expense of the CPU and GPU, can it?

Would going with a wide bus prevent them from moving to a narrower bus if more advanced RAM chips come out?

Sure, but how many people bought a PS3 because it played Bluray movies? When it launched, a PS3 was the cheapest Bluray player there was and its probably it's main function for most people today. Spending extra money on a 256 bit bus won't have the same benefits.

 

[jonabbey]

Sure, but how many people bought a PS3 because it played Bluray movies? When it launched, a PS3 was the cheapest Bluray player there was and its probably it's main function for most people today.

That's a bit harsh, don't you think?

Spending extra money on a 256 bit bus won't have the same benefits.

It depends on how much extra it costs. Sony has been hurt a lot this generation by being a year late and having the worse version of multiplatform games. If Sony had made up for the late launch by having more RAM or demonstrably better graphics on multiplatform games, the 360 wouldn't have done nearly as well as it did this generation.

But, any such money went to Cell and Blu-Ray development, I guess.

 

[Kaotik]

Would going with a wide bus prevent them from moving to a narrower bus if more advanced RAM chips come out?

Yes it would, you can't go cutting the bus, console specs are set not to be messed with after launch - if you do dieshrink, you keep the specs otherwise the same.

And dieshrinks would give yet another challenge - the chip not only has to be bigger to begin with to be able to house 256bit bus, but it also needs to stay big enough despite of shrinks to house it.