AMD To Launch Radeon HD4890 "RV790" In April

[largon]

If you look at the DDR 5 roadmaps you can come to the conclusion that memory bandwidth is going to be a non issue for the next 2 years or more. 256 bit differential ddr 5 will have something like 20x the bandwith as 512 bit ddr 3. In the same time period GPU performance with increase by 2x at best.

Meaning <256bit buses will become viable for performance parts. Within, say one year, a 128bit bus with conservative speed bin of differential GDDR5 will easily outperform current 256bit GDDR5 solutions, let alone 512bit GDDR3...

[RVWinkle]

Meaning <256bit buses will become viable for performance parts. Within, say one year, a 128bit bus with conservative speed bin of differential GDDR5 will easily outperform current 256bit GDDR5 solutions, let alone 512bit GDDR3...

I would say that the GTX285 will be the last video card you'll ever see with a 512bit bus but you know they're going to rename it in a few months lol.

[grimREEFER]

remember ppl, 512bit and gddr5 are not mutually exclusive for next gen cards.
they will have silly amount of bandwidth. why? because they are from the effin future, and have to make current gen cards look slow.

[zerazax]

remember ppl, 512bit and gddr5 are not mutually exclusive for next gen cards.
they will have silly amount of bandwidth. why? because they are from the effin future, and have to make current gen cards look slow.

Um, having bandwidth but leaving it unused means that the bandwidth is just wasted.

And, since having larger memory buses means more room being wasted on the chip, they're going to opt for smaller buses so you can get more die per wafer, and ultimately make GPU's cheaper.

[gamervivek]

GDDR5 is QDR... 50mhz = 200mhz


and I repeat that even in synthetics you only see an increase within the margin of error if at all. 4870's gddr5 is well capable of 1200mhz + so care to explain to me why world record 4870x2 benches are only run at 1000mhz ? its because there is an excess of bandwidth.

i guess calling it Graphics Double Data Rate was a stupid idea then?
not sure about all benchmarks but memory bandwidth wouldn't do as much for benchmarks without AA,just like 4850 does well for its core speed when compared to 4870without AA but falls back more than the core speed difference when AA is set to 4x and especially 8x.

[SNiiPE_DoGG]

i guess calling it Graphics Double Data Rate was a stupid idea then?
not sure about all benchmarks but memory bandwidth wouldn't do as much for benchmarks without AA,just like 4850 does well for its core speed when compared to 4870without AA but falls back more than the core speed difference when AA is set to 4x and especially 8x.

I think youve got something with the AA I wish I still had my single 4870 to play with under water..... then I could actually give us some real info to work with

[ToTTenTranz]

ATI's upcoming 55nm RV790 is the first new chip to come from ATI in the next quarter. We were told to expect it in April time and, at the same time, we learned that RV740, ATI's first desktop 40nm chip should start shipping a bit later.


ATI focuses on the mobile side and has Asus' first notebook design win with 40nm RV740, while desktop parts might start shipping either in late April or in early May time. ATI definitely have caught Nvidia by surprise as Nvidia simply didn’t believe that ATI will beat them to a new manufacturing process once again.

ATI was faster to transition to 65nm, 55nm and now even 40nm so Nvidia will have to wait for 32nm to try to beat ATI which is faster with new shrunk chips. We still have to see Nvidia’s first 40nm GPUs or even hear solid news about the state and availability of such products.

I guess that 40nm RV790 was just a typo after all

[seanx]

(RV770) AMD had to deal with pin-counts and bonding pads. 512bit would have needed a much bigger die-size just because of the pin-counts and bonding pads. Making the chip bigger would mean less chips per wafer, lower yields etc, higher prices etc. 512bit also doesn't add much performance.

maybe , but do u have proof of this ?
I remember stories of nvidia 512bit cards vs 256bit cards and the theory then
was they didn't "upgrade" the 256bit ones to 512bit purely as a marketing
point , since the alleged preformance of 256bit card (upgraded to 512bit) would be equal to the standard 512bit one....

And I aggree with the idea that the 4870x2 for example is suffering from the
256bit bottle neck ....seems to make sense.
just my useless 5c lol..

[Shadowmage]

maybe , but do u have proof of this ?

Yes. Dave Baumann, who's a senior manager at AMD/ATI, confirmed this on Beyond3D forums.

[ownage]

maybe , but do u have proof of this ?

Yes. Dave Baumann, who's a senior manager at AMD/ATI, confirmed this on Beyond3D forums.

And CJ, another ATI guy.

[Hell Hound]

Um,there cores are not fast enough so they sing some other sad song.Geforce used 512bit and performance was great.Dont give us excuses give us POWER. Plus they are a lot of games that love bandwidth,So how is it wasted.

[SNiiPE_DoGG]

Um,there cores are not fast enough so they sing some other sad song.Geforce used 512bit and performance was great.Dont give us excuses give us POWER.

Different architectures, different die sizes, different cards. that doesnt really make any sense.

[ownage]

Um,there cores are not fast enough so they sing some other sad song.Geforce used 512bit and performance was great.Dont give us excuses give us POWER. Plus they are a lot of games that love bandwidth,So how is it wasted.

The pros simply have to outweigh the cons.
They could have made the RV770 'virtually' (As CJ described) bigger/larger so pin-counts and bonding pads wouldn't be a problem, it also would have result in a much cooler chip. The same chip, but just made bigger. The pros of a small economical die was probably more rewarding than a big 512bit chip.

[Hell Hound]

The pros simply have to outweigh the cons.
They could have made the RV770 'virtually' (As CJ described) bigger/larger so pin-counts and bonding pads wouldn't be a problem, it also would have result in a much cooler chip. The same chip, but just made bigger. The pros of a small economical die was probably more rewarding than a big 512bit chip.

They could have adjusted the price accordingly.Also a cooler chip is what everyone wants,and what they need,I saw at least 100 pages of 4870 overheating threads,Which also hurt sales.

[LordEC911]

They could have adjusted the price accordingly.Also a cooler chip is what everyone wants,and what they need,I saw at least 100 pages of 4870 overheating threads,Which also hurt sales.

So you think it is cost effective to increase your costs/expenses by nearly double, leaving the performance the same, and somehow sell the same chip for more just because it is a couple of degrees cooler?

[Hell Hound]

Why would performance be the same.Some titles will and some will not benefit.Doesn't aa perf get's better with faster and more memory bandwidth.

[Hell Hound]

So you think it is cost effective by leaving the performance the same, and somehow sell the same chip for more just because it is a couple of degrees cooler?

Sounds like a HIS card to me.

[SNiiPE_DoGG]

AA perf of the RV7XX arch is already great, especially 8, what it needs is more texture power and the obligatory shader power to go with it.

[Hell Hound]

Where's my single card 16x aa.

[SNiiPE_DoGG]

8xaa is excessive once you are at 1920x1200 or higher... the more pixels the less AA is needed in the first place. AA is actually an image quality "patch" if you will, more to compensate for low resolution than to increase quality of the image

[DeathTyrant]

^Which explains why I didn't really need much in the way of AA on my old 2048x1536 CRT 19" monitor.^

[Bo_Fox]

8xaa is excessive once you are at 1920x1200 or higher... the more pixels the less AA is needed in the first place. AA is actually an image quality "patch" if you will, more to compensate for low resolution than to increase quality of the image

Nah, I still crave for 8xAA on my 1920x1200 LCD when I play Company of Heroes, or basically any other games. The jagged edges are just more pronounced on LCD screens than CRT's. I would guess that at 2560x1600, 8x is probably excessive, in my book at least.. After all, the resolution is king...

[Bo_Fox]

Guys, what if this is really a "cover-up" for the ultimate 40nm refresh of the same chip generation, like the 2900--> 3870? I wouldnt be surprised if ATI has caught Nvidia off-guard at this. At 40nm, even 950 MHz seems possible. It would just really make sense to have more TMU's.

With R800 that might include DX11 hardware, ATI really needs to improve anisostropic filtering so that it's no longer angle-dependent at 45 degrees. Come on, bring on 32x AF!!!!!!!!!!!!!!!!!!!!! At 2560x1600, we'd certainly see a big improvement in IQ with 32x AF.

[SNiiPE_DoGG]

rv770/790 is already dx11, it has programmable shaders so it doesnt need to be released specifically for DX11

[Bo_Fox]

That is, FULL DX11 hardware.. not just the tesselators or partial DX11 functions