The Radeon HD 4850 & 4870: AMD Wins at $199 and $299
by Anand Lal Shimpi & Derek Wilson on June 25, 2008 12:00 AM EST- Posted in
- GPUs
AMD's RV770 vs. NVIDIA's GT200: Which one is More Efficient?
It is one thing to be able to sustain high levels of performance and altogether another to do it efficiently. AMD's architecture is clearly the more area efficient compared to NVIDIA.
Alright now, don't start yelling that RV770 is manufactured at 55nm while GT200 is a 65nm part: we're taking that into account. The die size of GT200 is 576mm^2, but if we look at scaling the core down to 55nm, we would end up with a 412mm^2 part with perfect scaling. This is being incredibly generous though, as we understand that TSMC's 55nm half-node process scales down die size much less efficiently one would expect. But lets go with this and give NVIDIA the benefit of the doubt.
First we'll look at area efficiency in terms of peak theoretical performance using GFLOPS/mm^2 (performance per area). Remember, these are just ratios of design and performance aspects; please don't ask me what an (operation / (s * mm * mm)) really is :)
| Normalized Die Size | GFLOPS | GFLOPS/mm^2 | |
| AMD RV770 | 260 mm^2 | 1200 | 4.62 |
| NVIDIA GT200 | 412 mm^2 | 933 | 2.26 |
This shows us that NVIDIA's architecture requires more than 2x the die area of AMD's in order to achieve the same level of peak theoretical performance. Of course theoretical performance doesn't mean everything, especially in light of our previous discussion on extracting parallelism. So let's take a look at real performance per area and see what we get in terms of some of our benchmarks, specifically Bioshock, Crysis, and Oblivion. We chose these titles because relative performance of RV770 is best compared to GT200 in Bioshock and worst in Oblivion (RV770 actually leads the GT200 in bioshock performance while the GT200 crushes RV770 in Oblivion). We included Crysis because it's engine is quite a popular and stressful benchmark that falls somewhere near the middle of the range in performance difference between RV770 and GT200 in the tests we looked at.
These numbers look at performance per cm^2 (because the numbers look prettier when multiplied by 100). Again, this doesn't really show something that is a thing -- it's just a ratio we can use to compare the architectures.
| Performance per Die Area | Normalized Die Size in cm^2 | Bioshock | Crysis | Oblivion |
| AMD RV770 | 2.6 | 27 fps/cm^2 | 11.42 fps/cm^2 | 10.23 fps/cm^2 |
| NVIDIA GT200 | 4.12 | 15.51 fps/cm^2 | 8.33 fps/cm^2 | 8.93 fps/cm^2 |
While it doesn't tell the whole story, it's clear that AMD does have higher area efficiency relative to the performance they are able attain. Please note that comparing these numbers directly doesn't yield anything that can be easily explained (the percent difference in frames per second per millimeter per millimeter doesn't really make much sense as a concept), which is part of why these numbers aren't in a graph but are in a table. So while higher numbers show that AMD is more area efficient, this data really doesn't show how much of an advantage AMD really has. Especially since we are normalizing sizes and looking at game performance rather than microbenches.
Some of this efficiency may come from architectural design, while some may stem from time spent optimizing the layout. AMD said that some time was spent doing area optimization on their hardware, and that this is part of the reason they could get more than double the SPs in there without more than doubling the transistor count or building a ridiculously huge die. We could try to look at transistor density, but transistor counts from AMD and NVIDIA are both just estimates that are likely done very differently and it might not reflect anything useful.
We can talk about another kind of efficiency though. Power efficiency. This is becoming more important as power costs rise, as computers become more power hungry, and as there is a global push towards conservation. The proper way to look at power efficiency is to look at the amount of energy it takes to render a frame. This is a particularly easy concept to grasp unlike the previous monstrosities. It turns out that this isn't a tough thing to calculate.
To get this data we recorded both frame rate and watts for a benchmark run. Then we look at average frame rate (frames per second) and average watts (joules per second). We can then divide average watts by average frame rate and we end up with: average joules / frames. This is exactly what we need to see energy per frame for a given benchmark. And here's a look at Bioshock, Crysis and Oblivion.
| Average energy per frame | Bioshock | Crysis | Oblivion |
| AMD RV770 | 4.45 J/frame | 10.33 J/frame | 11.07 J/frame |
| NVIDIA GT200 | 5.37 J/frame | 9.99 J/frame | 9.57 J/frame |
This is where things get interesting. AMD and NVIDIA trade off on power efficiency when it comes to the tests we showed here. Under Bioshock RV770 requires less energy to render a frame on average in our benchmark. The opposite is true for Oblivion, and NVIDIA does lead in terms of power efficiency under Crysis. Yes, RV770 uses less power to achieve it's lower performance in Crysis and Oblivion, but for the power you use NVIDIA gives you more. But RV770 leads GT200 in performance under Bioshock while drawing less power, which is quite telling about the potential of RV770.
The fact that this small subset of tests shows the potential of both architectures to have a performance per watt advantage under different circumstances means that as time goes on and games come out, optimizing for both architectures will be very important. Bioshock shows that we can achieve great performance per watt (and performance for that matter) on both platforms. The fact that Crysis is both forward looking in terms of graphics features and shows power efficiency less divergent than Bioshock and Oblivion is a good sign for (but not a guarantee of) consistent performance and power efficiency.
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FITCamaro - Wednesday, June 25, 2008 - link
Yes I noticed it used quite a bit at idle as well. But its load numbers were lower. And as the other guy said, they probably just are still finalizing the drivers for the new cards. I'd expect both performance and idle power consumption to improve in the next month or two.derek85 - Wednesday, June 25, 2008 - link
I think ATI is still fixing/finalizing the Power Play, it should be much lower when new Catalyst comes out.shadowteam - Wednesday, June 25, 2008 - link
If a $200 card can play all your games @ 30+fps, does a $600 card even make sense knowing it'll do no better to your eyes? I see quite a few NV biased elements in your review this time around, and what's all that about the biggest die size TSMC's every produced? GTX's die may be huge, but compared to AMD's, it's only half as efficient. Your review title, I think, was a bit harsh toward AMD. By limiting AMD's victory only up to a price point of $299, you're essentially telling consumers that NV's GTX 2xx series is actually worth the money, which is a terribly biased consumer advice in my opinion. From a $600 GX2 to a $650 GTX 280, Nvidia's actually gone backwards. You know when we talk about AMD's financial struggle, and that the company might go bust in the next few years... part of the reason why that may happen is because media fanatics try to keep things on an even keel, and in doing so they completely forget about what the consumers actually want. No offence to AT, but I've been into media myself, and I can tell when even professionals sound biased.paydirt - Wednesday, June 25, 2008 - link
You're putting words into the reviewer(s) mouth(s) and you know it. I am pretty sure most readers know that bigger isn't better in the computing world; anandtech never said big was good, they are simply pointing out the difference, duh. YOU need to keep in mind that nVidia hasn't done a die shrink yet with the GTX 2XX...I also did not read anything in the review that said it was worth it (or "good") to pay $600 on a GPU, did you? Nope. Thought so. Quit trying to fight the world and life might be different for you.
I'm greatful that both companies make solid cards that are GPGPU-capable and affordable and we have sites like anandtech to break down the numbers for us.
shadowteam - Wednesday, June 25, 2008 - link
Are you speaking on behalf of the reviewers? You've obviously misunderstood the whole point I was trying to make. When you say in your other post that AT is a reviews site and not a product promoter, I feel terribly sorry you because reviews sites are THE best product promoters around, including AT, and Derek pointed this out earlier that AT's too influential to ignore by companies. Well if that is truly the case, why not type in block letters how NV's trying to rip us off, for consumers' sake, may be just for once do it, it'll definitely teach Nvidia a lesson.DaveninCali - Wednesday, June 25, 2008 - link
I completely agree. Anand, the GTX 260/280 are a complete waste of money. You are not providing adequate conclusions. Your data speaks for itself. I know you have to be "friendly" in your conclusions so that you don't arouse the ire of nVidia but the launch of the 260/280 is on the order of the FX series.I mean you can barely test the cards in SLI mode due to the huge power constraints and the price is ABSOLUTELY ridiculous. $1300 for SLI GTX 280. $1300!!!! You can get FOUR 4870 cards for less than this. FOUR OF THEM!!!! You should be screaming how poorly the GTX 280/260 cards are at these performance numbers and price point.
The 4870 beats the GTX 260 in all but one benchmark at $100 less. Not to mention the 4870 consumes less power than the GTX 280. Hell, the 4870 even beats the GTX 280 in some benchmarks. For $350 more, there shouldn't even be ONE game that the 4870 is better at than the GTX 280. Not even more for more than 100% of the price.
I'm not quite sure what you are trying to convey in this article but at least the readers at Anandtech are smart enough to read the graphs for themselves. Given what has been written in the conclusion page (3/4 of it about GPGPU jargon that is totally unnecessary) could you please leave the page blank instead.
I mean come on. Seriously! $1300 compared to $600 with much more performance coming from the 4870 SLI. COME ON!! Now I'm too angry to go to bed. :(
DaveninCali - Wednesday, June 25, 2008 - link
Oh and one other thing. I thought Anandtech was a review site for the consumer. How can you not warn consumers from spending $650 much less $1300 on a piece of hardware that isn't much faster and in some cases not faster at all than another piece of hardware priced at $300/$600 in SLI. It's borderline scam.When you can't show SLI numbers because you can't even find a power supply that can provide the power, at least an ounce of criticism should be noted to try and stop someone from wasting all that money.
Don't you think that consumers should be getting some better advise than this. $1300 for less performance. I feel so sad now. Time to go to sleep.
shadowteam - Wednesday, June 25, 2008 - link
It reminds of that NV scam from yesteryears... I'm forgetting a good part of it, but apparently NV and "some company" racked up some forum/blog gurus to promote their BS, including a guy on AT forums who eventually got rid off due to his extremely biased posts. If AT can do biased reviews, I can pretty much assure you the rest of the reviewers out there are nothing more than just misinformed, over-arrogant media puppets. To those who disagree w/ me or the poster above, let me ask you this... if you were sent out $600 hardware every other week, or in AT's case, every other day (GTX280's from NV board partners), would you rather delightfully, and rightfully, piss NV off, or shut your big mouth to keep the hardware, and cash flowing in?DerekWilson - Wednesday, June 25, 2008 - link
Wow ...I'm completely surprised that you reacted the way you did.
In our GT200 review we were very hard on NVIDIA for providing less performance than a cheaper high end part, and this time around we pointed out the fact that the 4870 actually leads the GTX 260 at 3/4 of the price.
We have no qualms about saying anything warranted about any part no matter who makes it. There's no need to pull punches, as what we really care about are the readers and the technology. NVIDIA really can't bring anything compelling to the table in terms of price / performance or value right now. I think we did a good job of pointing that out.
We have mixed feelings about CrossFire, as it doesn't always scale well and isn't as flexible as SLI -- hopefully this will change with R700 when it hits, but for now there are still limitations. When CrossFire does work, it does really well, and I hope AMD work this out.
NVIDIA absolutely need to readjust the pricing of most of their line up in order to compete. If they don't then AMD's hardware will continue to get our recommendation.
We are here because we love understanding hardware and we love talking about the hardware. Our interest is in reality and the truth of things. Sometimes we can get overly excited about some technology (just like any enthusiast can), but our recommendations always come down to value and what our readers can get from their hardware today.
I know I can speak for Anand when I say this (cause he actually did it before his site grew into what it is today) -- we would be doing this even if we weren't being paid for it. Understanding and teaching about hardware is our passion and we put our heart and soul into it.
there is no amount of money that could buy a review from us. no hardware vendor is off limits.
in the past companies have tried to stop sending us hardware because they didn't like what we said. we just go out and buy it ourselves. but that's not likely to be an issue at this point.
the size and reach of AnandTech today is such that no matter how much we piss off anyone, Intel, AMD, NVIDIA, or any of the OEMs, they can't afford to ignore us and they can't afford to not send us hardware -- they are the ones who want an need us to review their products whether we say great or horrible things about it.
beyond that, i'm 100% sure nvidia is pissed off with this review. it is glowingly in favor of the 4870 and ... like i said ... it really shocks me that anyone would think otherwise.
we don't favor level playing fields or being nice to companies for no reason. we'll recommend the parts that best fit a need at a price if it makes sense. Right now that's 4870 if you want to spend between $300 and $600 (for 2).
While it's really really not worth the money, GTX 280 SLI is the fastest thing out there and some people do want to light their money on fire. Whatever.
i'm sorry you guys feel the way you do. maybe after a good night sleep you'll come back refreshed and see the article in a new light ...
formulav8 - Wednesday, June 25, 2008 - link
Even in the review you claim 4870 is a $400 performer. So why don't you reflect that in the articles title by adding it after the $300 price?? Would be better to do so I think anyways. :)Maybe say 4870 wins up to the $400 price point and likewise with the 4850 version up to the $250 price that you claimed in the article...
This tweak could be helpful to some buyers out there with a specific budget and could help save them some money in the process. :)
Jason