AMD RV770 refresh -> RV790

In the toms review it's about 10% faster than 4870. Right in line with 13% faster core and 8% faster memory. Of course thats been settled with the clock for clock comparisons.

Upclocking to 1Ghz would take it past stock 285 according to their composite frame rate graph of all games. But I have to suspect the ease of 1 ghz is overblown. If it oced that well the clocks would be higher. Also one of the review sites only oced it to 900mhz, suggesting thats all they could immediately hit.

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.
 
Something about the gamestar graphs.


Seems to indicate that RV790 is in want of further bandwidth still, especially in AA modes.
 
I remember a chart long back showing how bandwidth hungry RV770 can be. Showed performance with memory clocks below spec to beyond spec. Was pretty interesting.
 
Rangers said:
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.
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Not only that, but there was some talk about improved idle power consumption. Didn't seem to happen...
 
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.
 
Gamestar is apparently using Cat 9.3's which might affect negatively to HD4890 speed
 
mczak said:
Not only that, but there was some talk about improved idle power consumption. Didn't seem to happen...
Click to expand...

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
 
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... :???:
 
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.
 
Sound_Card said:
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.
Click to expand...
PowerPlay at RV770 launch wasnt working either.
 
http://www.xbitlabs.com/articles/video/display/radeon-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."
 
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.
 
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