ATI HD 4870 1024MB GDDR5 !!!

Nils

Distinguished
Aug 7, 2008
586
0
19,010
Club 3D has just released a 1GB version of the Radeon HD 4870. I have found no benchmarks about it so far, but if anyone else has, please report the website. I can't wait to see it compete against it's 512MB small brother.
 
Over at guru3d they have the 4850 version. It gives slightly better frame rates at higher resolutions. I'm sure the same will happen with the 4870, however, I wouldn't expect a lot from it right now.

the 256bit memory buss needs to be addressed for more performance.
 

homerdog

Distinguished
Apr 16, 2007
1,700
0
19,780

No it doesn't, GDDR5 can provide plenty of bandwidth on a 256 bit bus.
 

IndigoMoss

Distinguished
Nov 30, 2007
571
0
18,980
Yeah, hopefully we can get some benchies soon, but I'm not sure if it's going to make too big of a difference. Every card before it that launches at 512mb and later gets a 1GB has shown almost no performance increase (8800GT, 2900Pro, 3850,3870,8600GT LOL edition). But the GDDR5 might prove to be different.
 

Why? It already has more bandwidth than the GTX 260.
 

Nils

Distinguished
Aug 7, 2008
586
0
19,010


You can't compare it to the 4850 1G because that one has GDDR 3 wich has less bandwidth that GDDR5, present on the new 4870 1G.

The 4870 512MB has 115GB/s, so the 1G version will have that to. What's the problem with the memory interface?
 
i don't want to get into a big argument here.

The 4850 does have gddr3 memory. I was just trying to make the point that there would be a similar "increase" in performance between the 512 and 1gig cards.very little but at higher resolutions.

The 256bit memory interface.......... give me a 9600gt with a 512bit memory interface and I'll give you my 4870.
 

sseyler

Distinguished
May 14, 2008
207
0
18,690



swifty_morgan, you're making no sense. People are trying to tell you here that the advantage of having 1GB of memory on the HD 4850 is hindered by it's slower memory bandwidth (due to the combination of a 265-bit memory bus and GDDR3 memory). In the case of the HD 4870, the GDDR5 has a much higher data-rate, which more than compensates for the 256-bit bus while allowing bandwidth to exceed that of the GTX 260. This allows the HD 4870 to more capably use the full 1GB since it won't be bottle-necked when trying to access the larger video memory. The conclusion that can be drawn from this is that the HD 4870 will scale better with 1GB than the HD 4850 and suitably will offer a larger performance increase. I'll take a 512MB HD 4850 over your 1GB 9600 GT with a 512-bit memory bus any day.
 

Nils

Distinguished
Aug 7, 2008
586
0
19,010


Finally someone who understands me. :bounce:
 

sseyler

Distinguished
May 14, 2008
207
0
18,690



No need to put words in my mouth :non: . I never claimed a "really BIG" increase in performance, just performance that would scale better than the 1GB version of the HD 4850. Come on, let's be reasonable here.
 



AND exactly what did I say in my original response ?.......... b4 you guys started to slam me ????????????
 

sseyler

Distinguished
May 14, 2008
207
0
18,690



I'm having a tough time getting through your dense head :fou: . You were comparing the HD 4850s minimal increase in performance from the 512MB to the 1GB version,

"I'm sure the same will happen with the 4870, however, I wouldn't expect a lot from it right now."

whereas I was telling you that the comparison isn't completely valid given the faster memory used on the HD 4870. And by the way, no one was slamming you. You just decided to make ignorant statements that were bound to be corrected, like this one:

"the 256bit memory buss needs to be addressed for more performance."

I addressed this statement when I corrected your first statement.
 


Something silly like "the 256bit memory buss needs to be addressed for more performance. "

What does the 256bit bus have to do with performance?
The HD4870 (which you did mention just before this statement) has more bandwidth than the GTX260 and it's 448bit memory, so how important is bitwidth alone? Did a heck of alot for the HD2900 didn't it. [:thegreatgrapeape:5]

Redesigning the GPU and PCB to acomodate more bitwidth makes no sense, especially when that 256bit X2 soundly beat that 512bit GTX280.

Increasing the memory size is a relatively easy thing to do, so addressing that first makes more sense than bothering with the bitwidth.
Your statement about the HD4850 vs GF9600GT is overly simplistic at best. Gimme an HD4850 with a 1Ghz core and 2GB of 1.6 (6.4) Ghz memory and you can have your GTX280.
 

Plain Old Me

Distinguished
Jun 25, 2008
23
0
18,510
Anyone know pricing on the 1 gb model? I am guna pick one up when they come out. The 512 mb one would be fine for most games, but when you do higher resolutions the extra memory comes into play, but really the reason I need more memory is for working in 3d programs such as Maya, where memory can quickly be saturated...
 

Nils

Distinguished
Aug 7, 2008
586
0
19,010


512MB of DDR3 can get saturated when on a 256-bit interface, because you get about 70GB/s. Saturating 512MB DDR5 is a lot more harder because you have about 120GB/s. This makes it more interesting of putting an extra 512Mb on a card like that, because of the extra bandwidth you have left.

4850 = DDR3
4870 = DDR5

SO: don't compare !!!
 

homerdog

Distinguished
Apr 16, 2007
1,700
0
19,780

It was your suggestion that a 256 bit bus is insufficient for RV770 that got us all riled up. GDDR5 is still in its infancy and it is already clocking over 1GHz (4GHz effective). Testing indicates that the 4870 - even at its stock memclock of 900MHz - is very rarely bandwidth limited. Some ATI guys even stated that they were pad limited with RV770 (256bit bus was too big!) so they added 2 more SIMD blocks to fill up space!!

The HD4850 is a bit short on bandwidth at times, but that card is not intended as a high end part.
 

Nils

Distinguished
Aug 7, 2008
586
0
19,010
Alright, let's end this discussion about the memory interface here.

If anyone else has some other interesting info about this card, please post it.