[Autopsy] ATI Radeon HD 4870 Update: Review

[NapalmV5]

my apologies for the thread revival..

nice to see R7xx live up to the code name

[LaMpiR]

I just read Anand review. I must admit that I'm impressed with ATI. As for future rampage user, 4870 will be a good way to begin

[Shintai]

More than 100% CF scaling?

[Hornet331]

More than 100% CF scaling?

pure magic.

[zerazax]

Posted by DerekWilson in comments:

greater than 100% scaling is due to margin of error combination for both single card and dual card tests in the vast majority of cases.

we also tested single card performance on an nvidia system and crossfire performance on an intel system, so the different computers will also add margin of error.

two card solutions generally don't scale at greater than 100% except in extraordinarily odd situations (where rebalancing loads might help with scaling on both individual cards -- but that's odd and rare).

[Shintai]

Same error for both 4850 and 4870 and with 5%+ difference. More their testing method or drivers thats bugged.

And 2 cards will never scale more than 100%, never. Well with the exception of nVidia I guess if 1 card is also doing physics?

But besides that, 4850/9800GTX(+) looks like the cards to get. Or 4870 if higher, but its still hard to pay 50$ more for so little. And SLI/CF shows its uselessness as usual.

Its also another round on how little improvement we get. 4850 is basicly 3870 and with same wattage. Same story with nVidia more or less. And their bigger cards scoring 20% more or so. Ultimo 2006 was the year of the big wall

[biohead]

>100% scaling could be that the 512MB with a single card isn't enough and the CF setup does act like 1GB instead of mirrored 2*512MB.

Margin of error sounds more plausible, though.

[Shintai]

>100% scaling could be that the 512MB with a single card isn't enough and the CF setup does act like 1GB instead of mirrored 2*512MB.

Margin of error sounds more plausible, though.

LOL..1GB? Also more memory does nothing basicly if you dont need it for texture size. And CF/SLI is ALWAYS and will ALWAYS be YxMemory and never a combined memory in any way.

It might actually more be a sync issue and some burst in FPS with crappy min FPS.

[halo112358]

More than 100% CF scaling?

Questionable, yes - wrong based on speculation, no. Ask for more tests, don't call BS just yet. Remember that CF is suppsed to be improved with the 4xxx generation, so instead of having 2 cores with 512 total memory (3xxx) you have 2 cores with 1gb total memory.

[Shintai]

Questionable, yes - wrong based on speculation, no. Ask for more tests, don't call BS just yet. Remember that CF is suppsed to be improved with the 4xxx generation, so instead of having 2 cores with 512 total memory (3xxx) you have 2 cores with 1gb total memory.

No, you have 2 cores with 2x512MB thats completely inaccessible to each other. And even if CF is improved, you still cant scale more than 100%. And no, there is no magic...

[v_rr]

No, you have 2 cores with 2x512MB thats completely inaccessible to each other. And even if CF is improved, you still cant scale more than 100%. And no, there is no magic...

The CrossFire Sideport

Although AMD isn't talking about it now, the CrossFire Sideport is a new feature of the RV770 architecture that isn't in use on the RV770 at all. In future, single-card, multi-GPU solutions (*cough* R700) this interface will be used to communicate between adjacent GPUs - in theory allowing for better scaling with CrossFire. We'll be able to test this shortly as AMD is quickly readying its dual-GPU RV770 card under the R700 codename.

One thing is for sure, anything AMD can do to assist in providing more reliable consistent scaling with CrossFire will go a long way to help them move past some of the road blocks they currently have with respect to competing in the high end space. We're excited to see if this really makes a difference, as currently CrossFire is performed the same way it always has been: by combining the output of the rendered framebuffer of two cards. Adding some sort of real GPU-to-GPU communication might help sort out some of their issues.

http://www.anandtech.com/video/showdoc.aspx?i=3341&p=9

Stop those astrologic preditions. Lets wait and see. You also said 100 times that HD 4800 suck, but sorry they don´t, actualy is the opose.
So before you say 100 times that R700 is like R680 wait those astrological power and lets see what R700 bring to the table.
There are new things that may come to be very interesting

[Shintai]

http://www.anandtech.com/video/showdoc.aspx?i=3341&p=9

Stop those astrologic preditions. Lets wait and see. You also said 100 times that HD 4800 suck, but sorry they don´t, actualy is the opose.
So before you say 100 times that R700 is like R680 wait those astrological power and lets see what R700 bring to the table.
There are new things that may come to be very interesting

First of all, this aint X2 card is it? No thats right, its 2 card CF. No magic there.

I never said 4800 series as such sucked. Its just not the divine reborn of chirst that you and a few others think. There is a reason its 199 and 299$ and not 299 and 499$. Unless you think AMD think its funny to lose money. nVidia instantly countered the 4850 card as expected in price. Since most of us non fanboys knows nVidia milked us for their record after record profits.

4850 is basicly=3870 and 4870 is some 20% faster. Its not exactly spectacular performance wise. But luckly enough, GT200 aint either.

And I sure hope it has a corssfire sideport. What do you think goes through the ribbon? I´m sure you can find a hype that can go crazy enough until its utter failure before the R700 release. Plus it might only fix some of the issues. As always the R700 will jump from excelent performance and down to 4870 performance or even below.

[Donnie27]

we also tested single card performance on an nvidia system and crossfire performance on an intel system, so the different computers will also add margin of error.

Before you guys start talking about errors, shouldn't we see results of one card, then two in CF on the same platform? Plus for many of us, I'd wish they'd do nVidia's Intel systems as an after thought LOL!

[v_rr]

First of all, this aint X2 card is it? No thats right, its 2 card CF. No magic there.

It´s a diferent crossfire because R700 will use a new feature that 2x RV770 in one mainboard can not use.

I never said 4800 series as such sucked. Its just not the divine reborn of chirst that you and a few others think.

You are the first trashing HD4800 everywhere. And if HD 4800 is not the reborn of chirst it is very close for the reactions we have seen

There is a reason its 199 and 299$ and not 299 and 499$. Unless you think AMD think its funny to lose money. nVidia instantly countered the 4850 card as expected in price. Since most of us non fanboys knows nVidia milked us.

The reason is writen everywere. First AMD target more volume (200-300$ market), and second HD 4800 cards are less expensive to produce. It´s writen everywere I don´t need to guess.
And AMD want to get back lost market share in the next 2 quarters and that´s the way to go -> strong performance and less expensive then competiton.

And I sure hope it has a corssfire sideport. What do you think goes through the ribbon?

I am not sure of nothing. I simply wait knowing that is there something new in R700. I just don´t start trashing the card.

[Shintai]

You are the first trashing HD4800 everywhere. And if HD 4800 is not the reborn of chirst it is very close for the reactions we have seen

I think that part explains your objectiveness, or lack of same. 20% boost on a highend card is.....in short you need nVidia to fail to get success?

[halo112358]

No, you have 2 cores with 2x512MB thats completely inaccessible to each other. And even if CF is improved, you still cant scale more than 100%. And no, there is no magic...

No, that's not true - the whole point of redesigning crossfire for the 4xxx series was to share the total pool of vram among the cores (think of it as using each card as a stick of dram, it's all the same pool to the processor).

Keep in mind this was a design goal, we won't know if they succeeded until the both the 4850 and 4870's have been put through the paces for a couple of weeks.

[v_rr]

I think that part explains your objectiveness, or lack of same. 20% boost on a highend card is.....in short you need nVidia to fail to get success?

Yeah, keep troling and spam around the forum as always. Hope your astrological power don´t fail next time

[Frodin]

4850 is basicly=3870 and 4870 is some 20% faster. Its not exactly spectacular performance wise. But luckly enough, GT200 aint either.

Your knowledge or ability to keep up with the tests is not exactly spectacular either, but that does not suit the purpose of threadcrapping on each and every thread about an AMD/ Ati product, does it? The 4850 is more than 50% faster than the 3870 in quite a few test. Read up or shut up.
http://anandtech.com/video/showdoc.aspx?i=3341&p=15

[Seraphiel]

More than 100% CF scaling?

It is kinda rare but not completely unexplainable

[ToTTenTranz]

LOL..1GB? Also more memory does nothing basicly if you dont need it for texture size. And CF/SLI is ALWAYS and will ALWAYS be YxMemory and never a combined memory in any way.

It might actually more be a sync issue and some burst in FPS with crappy min FPS.

"Always" and "never" are the worst words to use in a technology-related discussion. You managed to put them both in the same sentence.

IMHO, that makes you incapable for this discussion..

[STaRGaZeR]

No, that's not true - the whole point of redesigning crossfire for the 4xxx series was to share the total pool of vram among the cores (think of it as using each card as a stick of dram, it's all the same pool to the processor).

Keep in mind this was a design goal, we won't know if they succeeded until the both the 4850 and 4870's have been put through the paces for a couple of weeks.

You're wrong. You're talking about the shared memory 4870X2 will have. 4850/70 Crossfire is still the same as always: two chips in two different PCBs with mirrored data in both cards.

[Seraphiel]

You're wrong. You're talking about the shared memory 4870X2 will have. 4850/70 Crossfire is still the same as always: two chips in two different PCBs with mirrored data in both cards.

The shared memory makes it not quite the same as having two different PCBs by default, right? 2 x 512 MB = 1024 MB with the shared memory, but with SLI and CF, 2 x 512 MB = 512 MB. I am not saying it will yield better performance, time will tell about that, just that there is a significant difference. VRAM is of concern when going to XHD resolution and maxed settings, and 512 MB isn't always enough.


But concerning Shintai's previous statements that CF/SLI is a gimmick because it can't scale well, or that "magic" >100% scaling isn't possible.

Here are some screenshots with and without SLI...

SLI ON:
http://img374.imageshack.us/my.php?image=me1iw8.jpg

SLI OFF:
http://img108.imageshack.us/my.php?image=me2mn7.jpg

20 vs 9 fps... Yeah, both are not playable but it was an easy and extreme example to do in those few minutes since my last post.

I can do more reasonable and playable ones...

[STaRGaZeR]

The shared memory makes it not quite the same as having two different PCBs by default, right? 2 x 512 MB = 1024 MB with the shared memory, but with SLI and CF, 2 x 512 MB = 512 MB. I am not saying it will yield better performance, time will tell about that, just that there is a significant difference. VRAM is of concern when going to XHD resolution and maxed settings, and 512 MB isn't always enough.

I'm saying 4850/70 Crossfire is absolutely no different from 3850/70, nothing about perfomance. You still need to mirror the data in both cards. 4870X2 is the only card that has something new with its shared memory pool. And if you do Crossfire with two 4870X2, internally you have 1GB (2x512), but you will have to mirror the same 1GB of data in both 4870X2's.

[perkam]

Check the 9600GT SLI reviews, I saw the same 100%+ SLI Scaling in some games. It's more of an application thing than a driver or bug thing.

Perkam

[Hornet331]

You're wrong. You're talking about the shared memory 4870X2 supposed to have. 4850/70 Crossfire is still the same as always: two chips in two different PCBs with mirrored data in both cards.

fixed.

the fact that there is a crossfire x side port doesn't automaticaly equals a shared memory.