ATI Radeon HD 4890 vs. NVIDIA GeForce GTX 275
by Anand Lal Shimpi & Derek Wilson on April 2, 2009 12:00 AM EST- Posted in
- GPUs
New Drivers From NVIDIA Change The Landscape
Today, NVIDIA will release it's new 185 series driver. This driver not only enables support for the GTX 275, but affects performance in parts across NVIDIA's lineup in a good number of games. We retested our NVIDIA cards with the 185 driver and saw some very interesting results. For example, take a look at before and after performance with Race Driver: GRID.
As we can clearly see, in the cards we tested, performance decreased at lower resolutions and increased at 2560x1600. This seemed to be the biggest example, but we saw flattened resolution scaling in most of the games we tested. This definitely could affect the competitiveness of the part depending on whether we are looking at low or high resolutions.
Some trade off was made to improve performance at ultra high resolutions at the expense of performance at lower resolutions. It could be a simple thing like creating more driver overhead (and more CPU limitation) to something much more complex. We haven't been told exactly what creates this situation though. With higher end hardware, this decision makes sense as resolutions lower than 2560x1600 tend to perform fine. 2560x1600 is more GPU limited and could benefit from a boost in most games.
Significantly different resolution scaling characteristics can be appealing to different users. An AMD card might look better at one resolution, while the NVIDIA card could come out on top with another. In general, we think these changes make sense, but it might be nicer if the driver automatically figured out what approach was best based on the hardware and resolution running (and thus didn't degrade performance at lower resolutions).
In addition to the performance changes, we see the addition of a new feature. In the past we've seen the addition of filtering techniques, optimizations, and even dynamic manipulation of geometry to the driver. Some features have stuck and some just faded away. One of the most popular additions to the driver was the ability to force Full Screen Antialiasing (FSAA) enabling smoother edges in games. This features was more important at a time when most games didn't have an in-game way to enable AA. The driver took over and implemented AA even on games that didn't offer an option to adjust it. Today the opposite is true and most games allow us to enable and adjust AA.
Now we have the ability to enable a feature, which isn't available natively in many games, that could either be loved or hated. You tell us which.
Introducing driver enabled Ambient Occlusion.
What is Ambient Occlusion you ask? Well, look into a corner or around trim or anywhere that looks concave in general. These areas will be a bit darker than the surrounding areas (depending on the depth and other factors), and NVIDIA has included a way to simulate this effect in it's 185 series driver. Here is an example of what AO can do:
Here's an example of what AO generally looks like in games:
This, as with other driver enabled features, significantly impacts performance and might not be able to run on all games or at all resolutions. Ambient Occlusion may be something some gamers like and some do not depending on the visual impact it has on a specific game or if performance remains acceptable. There are already games that make use of ambient occlusion, and some games that NVIDIA hasn't been able to implement AO on.
There are different methods to enable the rendering of an ambient occlusion effect, and NVIDIA implements a technique called Horizon Based Ambient Occlusion (HBAO for short). The advantage is that this method is likely very highly optimized to run well on NVIDIA hardware, but on the down side, developers limit the ultimate quality and technique used for AO if they leave it to NVIDIA to handle. On top of that, if a developer wants to guarantee that the feature work for everyone, they would need implement it themselves as AMD doesn't offer a parallel solution in their drivers (in spite of the fact that they are easily capable of running AO shaders).
We haven't done extensive testing with this feature yet, either looking for quality or performance. Only time will tell if this addition ends up being gimmicky or really hits home with gamers. And if more developers create games that natively support the feature we wouldn't even need the option. But it is always nice to have something new and unique to play around with, and we are happy to see NVIDIA pushing effects in games forward by all means possible even to the point of including effects like this in their driver.
In our opinion, lighting effects like this belong in engine and game code rather than the driver, but until that happens it's always great to have an alternative. We wouldn't think it a bad idea if AMD picked up on this and did it too, but whether it is more worth it to do this or spend that energy encouraging developers to adopt this and comparable techniques for more complex writing is totally up to AMD. And we wouldn't fault them either way.
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san1s - Thursday, April 2, 2009 - link
why didn't you post a page on how useless dx 10.1 is? I bet that there will be even less difference in gameplay with dx10.1 on compared to dx10 than physxAnandThenMan - Friday, April 3, 2009 - link
10.1 can bring some meaningful performance boosts.http://img7.imageshack.us/img7/1757/hd489064.jpg">http://img7.imageshack.us/img7/1757/hd489064.jpg
SiliconDoc - Monday, April 6, 2009 - link
ati can't do physx at all - so uhh, no performance boost there, EVER.Same with cuda.
Kinda likewise with this cool Vreveal clean up video thingie.
Same with the badaboom converter compared to ati's err(non mentioned terrible implementation)...lol hush hush!!! doesn't matter ! doesn't matter ! nothing going on there !
tamalero - Thursday, April 9, 2009 - link
hu, gpu phsyx gpu aceleration only helps when theres heavy physx caltulations.almost no game uses that heavy calculations nowadays.
besides, if you wanted physix to run, dont you need a second card to run physX while the other does the graphics?
I suspect thers a slowdown as well if the same graphic card does the work.
SiliconDoc - Friday, April 24, 2009 - link
Since you suspect there's a slowdown with PhysX enabled it points out two things to me : 1. you have no clue if there is because you don't have an nvidia card, indicating your red rooster issue.2. That's why you didn't get my point when the other poster linked to the other review and listed the various settings and I laughed while pointing out the NV said PhysX enabled.
_______
It's funny how your brain farts at just the wrong time, and you expose your massive experience weakness:
"you suspect" - you don't know.
Go whine at someone else, or don't at all. At least bring a peashooter to the gunfight.
Ever played War Monger or Mirror's Edge ? lol
No of course not! YOU CAN'T, until, you know.
yacoub - Thursday, April 2, 2009 - link
Given that you label the price for the GTX260-216 as $205, and in reality it's closer to $175, can we expect the 275 will be closer to $215 in short order?yacoub - Thursday, April 2, 2009 - link
Of course ATi has a hard launch of this product - its hardware appears from your description to be identical to existing hardware just with a slight clockspeed boost, where as the GTX-275 is actually a break between the 285 and the 260.Also the 275 is much more appealing given that it has actual hardware improvements over the 260 for just a bit more cash.
chrnochime - Thursday, April 2, 2009 - link
Did you actually bothered to read other comments wrt the fact that the RV790 is a respin, not just bump in gpu/mem clkspeed??And the actual hardware improvements that are just cut-down from the GTX295. Big deal. Appealing to the NV fanboys, sure.
7Enigma - Friday, April 3, 2009 - link
It's possible he saw the article before Anand/Gary corrected the table. Originally the table had identical numbers between the 4870 and 4890. And in the text they mentioned that it was basically an OC'd 4870. This could lead one to assume it was pretty much the same card. In the article (on the next page) they did mention quickly the high transistor count, but it was brushed over quickly and they didn't really go into detail about the differences (still waiting to get a response about the cooling solution changes).As for the rest of his post, he IS clearly an Nvidia fanboy, because the 4890 is clearly the better product in just about every case (not even looking at the OC'ing potential which seems to be very nice).
SiliconDoc - Monday, April 6, 2009 - link
Hmm, better in every case, without the overclocking potential ? lol He's a fanboy ?Is it better with Cuda, curing cancer with Folding, Vreveal clean up video recoding, forced game profiles, dual GPU game forcing ? Any of those have an as good equivalent ? NO NOT ONE.
So you know dude, he's not the fanboy...
The thing is, ati did a good job with the ring around the gpu 3m transistors to cut down frazzly electric - and gain a good overclock.
That they did well. They also added capacitors and voltage management to the card - an expense left - not mentioned in expense terms - including the larger die cost.
So, on the one hand we have a rebranded overclock that merely used the same type of core reworking that goes into a shrink, but optimized for clocks with a transistor band around the outside.
Not a core rework, but a very good refinement.
I knew the intricacies would be wailed about by the red fans, but not a one is going to note that the G80 is NOT the same as the G92b - the refinements happened there as well in the die shrink, and in between, just like they do on cpu revisions.
Since ATI was making and overclocking upgrade, they needed to ring the core - and make whatever rearrangements were neccessary to do that.
Purely rebrand ? Ahh, not really, but downclocking it to the old numbers may (likely) reveal it's identical anyway.
At that point rebrand is tough to get away from, since the nvidia rebrands offered core revision and memory/clock differences, as well.
I'll give ati a very slight edge because of the ring capacitors, which is interesting, and may be due to the ddr5, that made their core viable for competition to begin with, instead of just a 9800X equivalent, the 4850 - minus the extra capabilities - cuda, better folding, physx, forced sli, game profiles - etc... vreveal... and on and on - evga game drivers on release day - etc. - oh the uhh.. ambient occlusion and fear + many other game mods for it...
Anyway, tell me none of that matters with a straight face - and that face will be so red you'll have to pay in wampum at the puter store.