...and then disaster struck.

Or at least that's how it felt. The past few weeks have been incredibly tumultuous, sleepless, and beyond interesting. It is as if AMD and NVIDIA just started pulling out hardware and throwing it at eachother while we stood in the middle getting pegged with graphics cards. And we weren't just hit with new architectures and unexpected die shrinks, but new drivers left and right.

First up was GT200, which appeared in the form of the GeForce GTX 280 and GeForce GTX 260. Of course, both of those can be paired or tri-ed (if you will), but with two cards requiring at least a 1200W PSU we're a bit worried of trying three. Then came the randomness that was the accidental launch of the Radeon HD 4850 (albeit with no architectural information) and only a couple hours later we first heard about the 9800 GTX+ which is a die shrunk higher clocked 9800 GTX that is now publicly announced and will be available in July.

And now we have the other thing we've been working on since we finished GT200: RV770 in all it's glory. This includes the 4850 whose performance we have already seen and the Radeon HD 4870: the teraflop card that falls further short of hitting its theoretical performance than NVIDIA did with GT200. But theoretical performance isn't reality, and nothing can be done if every instruction is a multiply-add or combination of a multiply-add and a multiply, so while marketing loves to trot out big numbers we quite prefer real-world testing with games people will actually play on this hardware.

But before we get to performance, and as usual, we will want to take as deep a look into this architecture as possible. We won't be able to go as deep with RV770 as we could with GT200, as we had access to a lot of information both from NVIDIA and from outside NVIDIA that allowed us to learn more about their architecture. At the same time, we still know barely anything about the real design of either NVIDIA or AMD's hardware as they prefer to hold their cards very close.

This won't work long term, however. As we push toward moving compute intensive applications to the GPU, developers will not just want -- they will need low level architectural information. It is impossible to properly optimize code for an architecture when you don't know exact details about timing, latency, cache sizes, register files, resource sharing, and the like. While, this generation, we have decidedly more information from NVIDIA on how to properly program their architecture, we still need more from both AMD and NVIDIA.

And Now, the Rest of the Story

Last week was a weird teaser - we gave you the goods, without explaining what they were.

By now you know that the Radeon HD 4850 is the best buy at $199, but today we're able to tell you much about its inner workings as well as introduce its faster, more expensive sibling: the Radeon HD 4870.

ATI Radeon HD 4870 ATI Radeon HD 4850 ATI Radeon HD 3870
Stream Processors 800 800 320
Texture Units 40 40 16
ROPs 16 16 16
Core Clock 750MHz 625MHz 775MHz+
Memory Clock 900MHz (3600MHz data rate) GDDR5 993MHz (1986MHz data rate) GDDR3 1125MHz (2250MHz data rate) GDDR4
Memory Bus Width 256-bit 256-bit 256-bit
Frame Buffer 512MB 512MB 512MB
Transistor Count 956M 956M 666M
Manufacturing Process TSMC 55nm TSMC 55nm TSMC 55nm
Price Point $299 $199 $199

Priced at $299 the Radeon HD 4870 is clocked 20% higher and has 81% more memory bandwidth than the Radeon HD 4850. The GPU clock speed improvement is simply due to better cooling as the 4870 ships with a two-slot cooler. The memory bandwidth improvement is due to the Radeon HD 4870 using GDDR5 memory instead of GDDR3 used on the 4850 (and GDDR4 for 3870); the result is a data rate equal to 4x the memory clock speed or 3.6Gbps. The Radeon HD 4870 and 4850 both use a 256-bit memory bus like the 3870 before it (as well as NVIDIA's competing GeForce 9800 GTX), but total memory bandwidth on the 4870 ends up being 115.2GB/s thanks to the use of GDDR5. Note that this is more memory bandwidth than the GeForce GTX 260 which has a much wider 448-bit memory bus, but uses GDDR3 devices.

NVIDIA GeForce GTX 280 NVIDIA GeForce GTX 260 NVIDIA GeForce 9800 GTX ATI Radeon HD 4870 ATI Radeon HD 4850 ATI Radeon HD 3870
Memory Size 1GB 896MB 512MB 512MB 512MB 512MB
Memory Technology GDDR3 GDDR3 GDDR3 GDDR5 GDDR3 GDDR4
Memory Bus Width 512-bit 448-bit 256-bit 256-bit 256-bit 256-bit
Memory Clock 1107MHz 999MHz 1100MHz 900MHz 993MHz 1125MHz
Memory Data Rate 2.2Gbps 2.0Gbps 2.22Gbps 3.6Gbps 1.99Gbps 2.25Gbps
Memory Bandwidth 141.7GB/s 111.9GB/s 70.4GB/s 115.2GB/s 63.6GB/s 72.0GB/s

The use of GDDR5 enabled AMD to deliver GeForce GTX 260 class memory bandwidth, but without the pin-count and expense of a 448-bit memory interface. GDDR5 actually implements a number of Rambus-like routing and signaling technologies while still remaining a parallel based memory technology, the result is something that appears to deliver tremendous bandwidth per pin in a reliable, high volume solution.

AMD most likely took a risk on bringing GDDR5 to market this early and we do expect NVIDIA to follow suit, AMD is simply enjoying the benefits of jumping on the GDDR5 bandwagon early and getting it right, at least it seems that way. It wouldn't be too far fetched to imagine a 55nm GT200 die shrink with a 256-bit GDDR5 memory interface, it should allow NVIDIA to drop the price down to the $300 level (at least for the GTX 260).

As we mentioned in our Radeon HD 4850 Preview, both the Radeon HD 4870 and 4850 now support 8-channel LPCM audio output over HDMI. AMD just sent over 8-channel LPCM drivers for the Radeon HD 4870 so we'll be testing this functionality shortly. As we mentioned in our 4850 preview:

"All of AMD's Radeon HD graphics cards have shipped with their own audio codec, but the Radeon HD 4800 series of cards finally adds support for 8-channel LPCM output over HDMI. This is a huge deal for HTPC enthusiasts because now you can output 8-channel audio over HDMI in a motherboard agnostic solution. We still don't have support for bitstreaming TrueHD/DTS-HD MA and most likely won't anytime this year from a GPU alone, but there are some other solutions in the works for 2008."

The Radeon HD 4870 is scheduled for widespread availability in early July, although AMD tells us that some cards are already in the channel. Given that the 4870 relies on a new memory technology, we aren't sure how confident we can be that it will be as widely available as the Radeon HD 4850 has been thus far. Keep an eye out but so far the 4850 has been shipping without any issues at $199 or below, so as long as AMD can get cards in retailers' hands we expect the 4870 to hit its $299 price point.

AMD's "Small-Die" Strategy
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  • 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. Reply
  • 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. Reply
  • 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.

    Reply
  • 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. Reply
  • 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. :(
    Reply
  • 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.
    Reply
  • 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? Reply
  • 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 ...
    Reply
  • 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
    Reply
  • paydirt - Wednesday, June 25, 2008 - link

    This is a review site. This isn't a site to market/promote products. Reply

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