AMD To Launch Radeon HD4890 "RV790" In April

[postumus]

Dang I'm in the market for a new card...and these are right around the corner, what to do?!

[MrHydes]

makes me sick all this rumors and stuff.

wouldn't be surprised if ATI is planting this news, fooling everyone around,

even tough they might bring a surprised as they did with RV770, but

i don't think so... 40nm TSMC process node is delayed... too bad

for their upcoming series.

[ILikeCosmosS]

ati is probably doing this rumors to confuse people therfore bigger supprise more money if they beat the 2 nvidia cards easily

( i died inside when ati said no 40nm , is 58xx series for octuber or june?)

[Dainas]

Well its plausible, with a return to the 512bit bus the RV790 could -just possibly- compete with a GTX 285... But that wouldnt be like this industry, where bending over and talking out one's.... err, talking big, is all the rage. 256bits of fail onward ho ATI.

Also, after all this time there ought to be a way to squeeze wider buses on a smaller, cheaper, although no less complex pcb.... so don't come at me with the cost effective philosophy, that was thrown out the window by GDDR4 and 5 use instead.

[largon]

Don't advertise a card with low idel consuption when its not true, and then even lie about "delivering" it later.

Link?

[Hornet331]

Link?

Just look up the pre launch presentations of the HD4800.

[LordEC911]

Well its plausible, with a return to the 512bit bus the RV790 could -just possibly- compete with a GTX 285... But that wouldnt be like this industry, where bending over and talking out one's.... err, talking big, is all the rage. 256bits of fail onward ho ATI.

Also, after all this time there ought to be a way to squeeze wider buses on a smaller, cheaper, although no less complex pcb.... so don't come at me with the cost effective philosophy, that was thrown out the window by GDDR4 and 5 use instead.

Ummm... because they would be pad limited.

[ownage]

So a slightly higher clocked 260GTX?

It is said that nVidia made some emergency calls to there board partners after they heard some rumors about RV790 performance. A phone call and the GTX-275 was born. More like a forced move for nVidia.

GTX-260 will be lowered to $179 to make room for the GTX-275.

Edit: Back on-topic!

[trinibwoy]

Said by whom? If Nvidia actually reacts to RV790 in such a clumsy and ineffective fashion they've really completely lost it. But at least it'll be consistent with all the other bonk they've been doing lately.

[SNiiPE_DoGG]

Well its plausible, with a return to the 512bit bus the RV790 could -just possibly- compete with a GTX 285... But that wouldnt be like this industry, where bending over and talking out one's.... err, talking big, is all the rage. 256bits of fail onward ho ATI.

Also, after all this time there ought to be a way to squeeze wider buses on a smaller, cheaper, although no less complex pcb.... so don't come at me with the cost effective philosophy, that was thrown out the window by GDDR4 and 5 use instead.

I dont get it.... the 256bit gddr5 4870 has an excess of bandwidth... even at 900 core I don't see improvements in even synthetics more that 1-2% by raising my ram clocks 50 mhz.

[onethreehill]

RV790 gets more efficient Powerplay
Source: ATI-Forum

On the CeBIT 2009 us 6 April was confirmed as release date by the RV790 of several partners. Now us new information was passed on to the current consumption.

So less river is to need after our enterprisenear sources of the RV790 in the Idle mode, than the RV770Pro in the no-load operation and under load reach a level of the RV770XT or are even somewhat under it. This has to do with the fact that one worked at AMD strongly on PowerPlay and also on a new 55nm manufacturing process, which is not to be compared with the manufacturing process of the RV770.

We will see whether these information is confirmed.

Translated

[Frodin]

So less river is to need after our enterprisenear sources of the RV790 in the Idle mode

Lovely!

[v_rr]

As I said ATI is spreading fud around RV790 spreading fake info around the web by sites and partners and Taiwan makers.
There is no point discussing the rumours we have so far.

Its a 40nm;it´s a 55nm; it´s a new 55nm; it´s the same with OC; it has more SP´s; it has more TMU and RBE´s; it has more clock.
This just don't have an end....

[ownage]

Well its plausible, with a return to the 512bit bus the RV790 could -just possibly- compete with a GTX 285... But that wouldnt be like this industry, where bending over and talking out one's.... err, talking big, is all the rage. 256bits of fail onward ho ATI.

Also, after all this time there ought to be a way to squeeze wider buses on a smaller, cheaper, although no less complex pcb.... so don't come at me with the cost effective philosophy, that was thrown out the window by GDDR4 and 5 use instead.

(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.

[Nedjo]

They cannot create a shader core with 1000SPs. It is 960 or 1040SPs.

why not?

280 to 285 is 20% more or less so why not?

it's more "of" and much less "or"

RV790 sounds like the R520->R580 refresh than a new node at this point

and that was a quite of refresh:

thisHD4890 is in my hands ...NOW and perf is higher only 10 percents above HD4870 1GB! Great improvement Great AMD! GTX 260 216 still better!

My own Sample of RV 790 is "like 4850" with clocks 850/900 MHz ... better model (like today 4870) with 950/975 MHz could be later, but maybe will never be launched !

shaders are not that important actually, RV770 has a good amount of raw power, it needs more texturing power IMO, thats the bottleneck of the chip

WRONG LOE

[Hornet331]

RV790 gets more efficient Powerplay
Source: ATI-Forum


Translated

uhng... not again... i only belive it when its really there.

[LordEC911]

why not?

Because of how the shader core is arranged.
RV770 has 10SIMDs, i.e. clusters, with 16 fat shaders in each cluster.
The next step up is 12SIMDs, 12*16=192*5=960.

If they add two more clusters, hit the clocks they are supposedly hitting and also reworked the ROPs this will be a nice filler before RV870 hits later this year.

[Dainas]

I dont get it.... the 256bit gddr5 4870 has an excess of bandwidth... even at 900 core I don't see improvements in even synthetics more that 1-2% by raising my ram clocks 50 mhz.

50 mhz is hardly anything with GDDR these days, also GDDR5 on 256bit is one of those things that by principle should have, but dosent really measure up to 512bit GDDR3. Latency or whatnot, dunno. But the HD4870 isnt flooded in wasted bandwidth like the 2900XT was for its day.

[trinibwoy]

why not?

The total has to be a multiple of the number of lanes per ALU and the number of ALUs per SIMD. Using 5 and 16 for those values as it stands today you can't arrive at 1000.

WRONG LOE

Vantage's texture tests are borked and disagree with every other texturing benchmark out there. FM has been "promising" to fix it for ages now. How did you manage to miss all the other texturing tests out there? I'm not convinced that RV770 is THAT texture bound though.

[SNiiPE_DoGG]

50 mhz is hardly anything with GDDR these days, also GDDR5 on 256bit is one of those things that by principle should have, but dosent really measure up to 512bit GDDR3. Latency or whatnot, dunno. But the HD4870 isnt flooded in wasted bandwidth like the 2900XT was for its day.

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.

[Vapor]

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.

The biggest reason is that it's pretty difficult to run the high vmem speeds with high system speeds

Basically, the harder you push the CPU/system end of the PC, the lower the 4870X2 memory has to go. It's a weird phenomenon, but it definitely happens.

[B.E.E.F.]

TBasically, the harder you push the CPU/system end of the PC, the lower the 4870X2 memory has to go. It's a weird phenomenon, but it definitely happens.

So the higher the GPU overclock means I have to underclock the memory??

[SNiiPE_DoGG]

So the higher the GPU overclock means I have to underclock the memory??

without voltmodding yes.... although when I was playing with my voltmodded 4870s I never noticed the need to go below 1000mhz. I wish I had more experience playing with Vmodded ram but alas I am always to impatient to get that mod done once I've sorted out the core mod

[OnLine]

The biggest reason is that it's pretty difficult to run the high vmem speeds with high system speeds

Basically, the harder you push the CPU/system end of the PC, the lower the 4870X2 memory has to go. It's a weird phenomenon, but it definitely happens.

Yes, I can only guess this problem is related to the GPU's memory controller.
Faster system, more stress on GPU's memory controller.

//

Texture Units
Texture Fetch Units
Texture Adress Units
Texture Mapping Units
Pixel Shader Texture Units
Vertex Shader Texture Units
?

When card X has worse/better texturing performance than card Y, it could be under some specific circumstances.

I don't know the difference between these, I know nothing, I say nothing. Hopefully RV790 will be more efficient/faster than RV770 at both shaders & textures.

[RVWinkle]

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.