[mczak]

Originally Posted by Rangers

Also interesting/poor how it sucks more juice at load than 285..sort of counter intuitive it could do that at nearly half the die size.

Not only that, but there was some talk about improved idle power consumption. Didn't seem to happen...

[mhouston]

Just a quick update. RV790 does *not* support burst memory reads, we had an error in our documentation that will be fixed and updated shortly, sorry about that. Y'all are just too quick scanning through things and finding nuggets like that. There are some tweaks in RV790, but burst reads is not one of them.

[Kaotik]

Gamestar is apparently using Cat 9.3's which might affect negatively to HD4890 speed

[AnarchX]

Originally Posted by Kaotik

Gamestar is apparently using Cat 9.3's which might affect negatively to HD4890 speed

Does Cat 9.3 even run on HD4890?
I would say they use 9.3 for 4870 and the 9.4b for 4890, which is packaged with it.

[digitalwanderer]

Originally Posted by AnarchX

Does Cat 9.3 even run on HD4890?

Didn't for me.

[Silent_Buddha]

Originally Posted by mczak

Not only that, but there was some talk about improved idle power consumption. Didn't seem to happen...

Eh? According to that Tom's Hardware shot, it has 30 watts more load and 30 watts less idle.

160/90 for 4870.
190/60 for 4890.

Although I'm taking that with a grain of salt until I see numbers from people I trust a bit more.

A bit disappointing for load power to go up almost 20% while Toms is showing it at a tad over 10% performance increase.

Either way, I'll wait and see how it does at Techreport, Xbit and Anandtech...

Regards,
SB

[Kyyla]

That looks nice. I guess I might not have to wait for that 285 price drop :P

[no-X]

Silent_Buddha: The idle power consumption is quite interesting issue, because some sources tells me that it's significantly lower (one of them mentioned 30W difference many days before the THG review was posted), while other suggest the same as for HD4870...

[Sound_Card]

Probably safe for me to say it now, but HD 4890 drops to 240mhz idle and idles at around 60w(which should be 30w less than HD 4870). If some test show other wise, it's either a bug or perhaps a RV770 mocking RV790 review.

[Arty]

Originally Posted by Sound_Card

Probably safe for me to say it now, but HD 4890 drops to 240mhz idle and idles at around 60w(which should be 30w less than HD 4870). If some test show other wise, it's either a bug or perhaps a RV770 mocking RV790 review.

PowerPlay at RV770 launch wasnt working either.

[Dave Baumann]

Originally Posted by Arty

PowerPlay at RV770 launch wasnt working either.

Yes it was.

[Kef]

http://www.xbitlabs.com/articles/vid...on-hd4890.html

In this review HD4890OC (900/3900) beats the GTX285 in 11 out of 16 tests and 1 draw (2560x1600). Pretty impressive!

"In the race again GeForce GTX 285 the regular Radeon HD 4890 wins in six tests out of fifteen, while the overclocked one wins in eleven and draws in one. The maximum lag in those tests it lost is only about 9%. This results into an average advantage of 13% in favor of new ATI solution.

The average performance gain over Radeon HD 4870 1GB in the highest resolution exceeds 13% and sometimes reaches 20%. Overclocking adds another 15% on average. The score is the same: 6:9 in Nvidia’s favor for the regular Radeon HD 4890 and 11:4 in favor of the overclocked ATI solution. This is a very good result for the card that wasn’t initially supposed to compete against the single-processor flagship product from the enemy camp."

[fellix]

Looks like the addition of the "decap ring" is responsible for the slight die area increase - click!

[Lightman]

In xbit article they saying RV790 transistor count grown from 956mln. to 959mln. Increase by 3 mln. transistors. This could be spent entirely on improved power circuity.

[Jawed]

3M transistors extra, this cap ring and no process change?

Jawed

[fellix]

a.k.a., RV770 done right!

[Ailuros]

Now let's see who's full of it exactly: http://www.theinquirer.net/inquirer/.../ati-4890-asic

[Jawed]

Originally Posted by fellix

a.k.a., RV770 done right!

Why did it take so long?

Conspiracy theory: this was a quick fix after their attempts to make a 40nm version failed or proved not worth the bother.

Jawed

[fellix]

Conspiracy theory: this was a quick fix after their attempts to make a 40nm version failed or proved not worth the bother.

(an optimistic view)
Or probably because RV800 design got so well on the 40nm node, that the bothering with the current generation didn't worth either way.

[Ailuros]

Originally Posted by fellix

(an optimistic view)
Or probably because RV800 design got so well on the 40nm node, that the bothering with the current generation didn't worth either way.

I wouldn't call that persective optimistic, but rather realistic and that goes for both IHVs.

[mczak]

Originally Posted by Kef

http://www.xbitlabs.com/articles/vid...on-hd4890.html
This is a very good result for the card that wasn’t initially supposed to compete against the single-processor flagship product from the enemy camp."

Note though that xbitlabs is testing with "high quality" driver options. Not wanting to start a fight here if that's fair or not, but some other reviews will use use default options which tends to help Nvidia's cards more than ATI (since they can't do "perfect" aniso filtering even with high quality). Might just make enough of a difference that even the OC cards can only compete with the GTX 285.

[mczak]

Originally Posted by mhouston

Just a quick update. RV790 does *not* support burst memory reads, we had an error in our documentation that will be fixed and updated shortly, sorry about that. Y'all are just too quick scanning through things and finding nuggets like that. There are some tweaks in RV790, but burst reads is not one of them.

Oh, that's interesting. Reviews now mention it supports memory bursts due to these docs.
I guess there's a good reason that it doesn't support this (doesn't it have to due to the 256bit memory bus or what?).

[fellix]

Looks like it is available only for the new 40nm parts (RV740 and its derivatives), so we should expect this feature in RV800 series for the high-end SKUs.

[pjbliverpool]

Originally Posted by Kef

http://www.xbitlabs.com/articles/vid...on-hd4890.html

In this review HD4890OC (900/3900) beats the GTX285 in 11 out of 16 tests and 1 draw (2560x1600). Pretty impressive!

The OC is actually 1000/4800. Its their own OC on the regular card, not the standard ATI OC of 900/3900.

So the OC scores shouldn't be paid too much attention since its not apples to apples, for a real comparison you would want to overclock the 285 as well.

Comparing to the standard 4890 at my playing resolution of 1920x1200 and ignoring synthetics, the scores stand at 8 wins for the 285, 5 wins for the 4890 and 2 draws.

So overall the 285 is still the fastest single GPU but not by much and the 4890 is extremely impressive given its price advantage and definatly a worthy alternative.

The real decider will be what kind of factory overclocks we see on the 4890 and what they sell for compared to the stock 285. It does seem that ATI could have a major winner on their hands here though. Kinda wish I was looking to buy at the moment but i'm holding out for the DX11 generation.

[Dave Baumann]

Originally Posted by mczak

I guess there's a good reason that it doesn't support this (doesn't it have to due to the 256bit memory bus or what?).

There are no logic design changes to HD 4890, the changes are done from a physical design point of view.