Possible ATI 4870 vs 9800GX2@Legit Reviews

[MooMasster716]

More news From Toms Hardware

http://www.tomshardware.com/news/ati-radeon-4800,5375.html

 

[largon]

i alrdy have an idea.....ITS going to be better then the 3870x2....why would a new gpu come out thats going to be worse? and they alrdy have benchs i posted a link earlier

HD3870X2 has two RV670 chips in case you haven't noticed.
As I said, 2x RV670 has more pretty much everything that matters for GPU performance (ROPs and shaders) then RV770 - and the same amount of TMUs. So I can't possbily understand how you'd expect RV770 to be over twice as fast as a single RV670.

 

[jokers_greg]

More news From Toms Hardware

http://www.tomshardware.com/news/ati-radeon-4800,5375.html

read that article. apparantly ATi's gonna try to fire this lineup around $200 starting, so i think that looks promising. Still waiting on reputable source evaluations, but only time will tell.

As far as trolling goes, i still dunno what it means. When i was on this forum daily a few years back i never even heard of the word.

 

[jokers_greg]

HD3870X2 has two RV670 chips in case you haven't noticed.
As I said, 2x RV670 has more pretty much everything that matters for GPU performance (ROPs and shaders) then RV770 - and the same amount of TMUs. So I can't possbily understand how you'd expect RV770 to be over twice as fast as a single RV670.

what about mem speeds. this would be a good time for an employee at ati to rush in here and tell me they'll be selling their flagship card for 200 dollars with 512-bit buses. On the side, is it just me or does it seem like OC's are more modest, on newer cards as opposed to 2-3 years ago.

 

[Neural Net]

Something is REALLY confusing me...

There's the 4850, 4870 and 4870X2, they're all 512MB a core, they're all r600 based...

But how can they have GDDR3 on the 50 and GDDR5 on the 70's? GDDR3 would be too slow with a 256-bit interface and GDDR5 is very expensive, but ATi has slated the 4870's price to be $240...

Well what I've read has suggested that GDDR5 is supposed to be relatively inexpensive to manufacture, and that 512bit DDR3 would be more expensive. Of course none of this information is concrete but that's what some websites have said for ATI's reasoning going to GDDR5.

 

[largon]

jokers_greg,
512bit bus wouldn't make sense on a card targeted @ $200. GDDR3/4 is 3-5 bucks per chip and GDDR5 will be ever more expensive at first so the memory alone would cost almost ½ of the retail asking price. That means 512bit isn't going to happen.

And besides, memory bandwidth is something that allows the GPU to perform better. It's not something that will automatically increase performance. As can be seen from R600 - OC'ing the 512bit bus makes almost no difference at all. 512bit bus is makes no sense if you can use memory - like GDDR5 - that is fast enough to reach comparable bandwidths with just 256bit bus width.

 

[onguardtech]

i really hope ATI kicks some nvidia butt this time around. Any idea on cost for this new card?

 

[jokers_greg]

jokers_greg,
512bit bus wouldn't make sense on a card targeted @ $200. GDDR3/4 is 3-5 bucks per chip and GDDR5 will be ever more expensive at first so the memory alone would cost almost ½ of the retail asking price. That means 512bit isn't going to happen.

And besides, memory bandwidth is something that allows the GPU to perform better. It's not something that will automatically increase performance. As can be seen from R600 - OC'ing the 512bit bus makes almost no difference at all. 512bit bus is makes no sense if you can use memory - like GDDR5 - that is fast enough to reach comparable bandwidths with just 256bit bus width.

this was the point of the post, The possibility of 512-bit bus on a $200 card that outperforms a 9800 GX2, is impossible. as impossible as a guy from ati signing up on ocforums to leak information to us. as for the mem, it could be a bottleneck on the GPU, i have yet to see those "no change" OC claims on the RV670

edit: the point of the 512-bit bus ALONG with GDDR3/4/5 is to allow more overclocking room, and ONLY more overclocking room.

 

[jokers_greg]

i really hope ATI kicks some nvidia butt this time around. Any idea on cost for this new card?

$199-$249. which seems almost too good to be true

 

[WorshipMe]

I heard the price of the HD 4870 was to be $300+.

 

[jokers_greg]

I heard the price of the HD 4870 was to be $300+.

look at the toms hardware link posted earlier. That is my definition of a reputable source, and they quoted the price i posted

 

[ratbuddy]

Basically it looks like the 4870 will use 4ghz GDDR5 clocked down to ~3.7ghz to save power. According to this, anyway: http://www.nordichardware.com/news,7728.html

Nvidia is sticking with GDDR3 for now, which would explain why they are thinking of a 512-bit bus, to make up for the slower memory. GDDR3 @ 1000mhz w/512-bit bus would have the same bandwidth as GDDR5 @ 2000mhz w/256-bit bus. Right?

 

[ghost_recon88]

Basically it looks like the 4870 will use 4ghz GDDR5 clocked down to ~3.7ghz to save power. According to this, anyway: http://www.nordichardware.com/news,7728.html

Nvidia is sticking with GDDR3 for now, which would explain why they are thinking of a 512-bit bus, to make up for the slower memory. GDDR3 @ 1000mhz w/512-bit bus would have the same bandwidth as GDDR5 @ 2000mhz w/256-bit bus. Right?

Nope, GDDR3 and GDDR5 do not work on the same clock cycle, just as is the case with desktop DDR2 and DDR3. The GDDR5 on a 256-bit would be a bit faster then the GDDR3 on a 512-bit.

 

[ratbuddy]

Nope, GDDR3 and GDDR5 do not work on the same clock cycle, just as is the case with desktop DDR2 and DDR3. The GDDR5 on a 256-bit would be a bit faster then the GDDR3 on a 512-bit.

Any idea how to calculate bandwidth?

 

[largon]

Nope, GDDR3 and GDDR5 do not work on the same clock cycle, just as is the case with desktop DDR2 and DDR3.

Technically, that makes no sense whatsoever.

The GDDR5 on a 256-bit would be a bit faster then the GDDR3 on a 512-bit.

How so?

 

[Neural Net]

Technically, that makes no sense whatsoever.
How so?

Technically? So I guess you know everything there is to know about Ram, and all what can affect performance is bus width and speed? Your question is valid just don't be so accusatory.

Here's some info.

 

[ratbuddy]

Technically? So I guess you know everything there is to know about Ram, and all what can affect performance is bus width and speed? Your question is valid just don't be so accusatory.

Here's some info.

That link doesn't qualify any of it's numbers, just a vague mention that this GDDR5 is 'more than twice as fast' as GDDR3.. Who knows what clocks they are talking about. Does anyone know the actual calculations for memory bandwidth as relates to GDDR3/4/5?

 

[Neural Net]

Read the damn article. It clearly states the bandwidth that GDDR5 has to offer in mass production for the first half of 2008. I'm fedup of posting links when nobody actually reads them, I hate spoon feeding, Google exists for a reason.

 

[ratbuddy]

Read the damn article. It clearly states the bandwidth that GDDR5 has to offer in mass production for the first half of 2008. I'm fedup of posting links when nobody actually reads them, I hate spoon feeding, Google exists for a reason.

Calm down. I can't find anything on google that tells me what GDDR5 even means. DDR, simple enough, it transfers information on both the rise and fall of the voltage signal.GDDR2.. Does it do 2 transfers per rise/fall? Is is just a marketing name? Ditto with GDDR3/4/5? All the information I can find by googling is geared towards people who already understand the technology involved. I'm fedup of people who will post vague links and expect everyone to understand the information without 'spoonfeeding'... Or do you not understand the numbers yourself?

If you can't say something nice, .... This thread is probably on shaky ground as it is...

Once again: Can someone who actually understands the way memory bandwidth is calculated show how to figure out the theoretical bandwidth of (for example) 1000mhz GDDR3 on a 512-bit bus compared to 2000mhz GDDR5 on a 256-bit bus? Would GDDR4 at 1500mhz on a 384-bit bus be the same thing???

 

[Neural Net]

Calm down. I can't find anything on google that tells me what GDDR5 even means. DDR, simple enough, it transfers information on both the rise and fall of the voltage signal.GDDR2.. Does it do 2 transfers per rise/fall? Is is just a marketing name? Ditto with GDDR3/4/5? All the information I can find by googling is geared towards people who already understand the technology involved. I'm fedup of people who will post vague links and expect everyone to understand the information without 'spoonfeeding'... Or do you not understand the numbers yourself?

If you can't say something nice, .... This thread is probably on shaky ground as it is...

Once again: Can someone who actually understands the way memory bandwidth is calculated show how to figure out the theoretical bandwidth of (for example) 1000mhz GDDR3 on a 512-bit bus compared to 2000mhz GDDR5 on a 256-bit bus? Would GDDR4 at 1500mhz on a 384-bit bus be the same thing???

In terms of the rough equations you're on the right track. I do understand the numbers in the articles. I'll try to find the article where it stated the greater efficiencies of GDDR5 over DDR3 and GDDR4 but I read it a while ago.