ATI Radeon HD 3870 & 3850: A Return to Competition
by Anand Lal Shimpi & Derek Wilson on November 15, 2007 12:00 AM EST- Posted in
- GPUs
Finally. We're finally getting somewhere interesting in the graphics industry. Although they're sure to return, the days of reviewing $600 graphics card after $600 graphics card are on hiatus, and instead we're reviewing a new class of mainstream cards with earth-shattering performance.
NVIDIA's GeForce 8800 GT kicked off the trend, in one fell swoop making almost all of NVIDIA's product line obsolete thanks to the high performance and low price tag (we'll talk about that last part shortly). But what we saw there wasn't a fluke, it was a preemptive strike against AMD, who have been hard at work on an affordable GPU of their own.
This new product, like the 8800 GT, would be aimed squarely at the $150 - $250 market segment, something both AMD and NVIDIA did a horrible job at with mainstream releases earlier this year (2600 and 8600 both sucked guys).
Introducing the RV670
AMD's two new graphics cards launching today are both based off a new GPU, referred to internally as the RV670. The basic architecture of the hardware is largely unchanged from R600; there has been some additional functionality added, and a great deal of internal bandwidth removed, but other than that this is very much an R600 based part.
The biggest news of this part is that it is fabbed on a 55nm TSMC process. This is a half-node process based on 65nm technology, giving AMD an advantage in die size (cost) and potentially clock speed and/or power.
Historically, AMD's RV series has been a cost cut version of their R series designed for lower end volume parts, and that's where RV670 started. Right of the bat, half the external and internal memory bandwidth of R600 was cut out. External bandwidth dropped from 512-bit to 256-bit, but AMD stuck with 8 memory channels (each dropped from 64bit to 32bit).
Internally, the ring bus dropped from 1024-bit to 512-bit. This cut in bandwidth contributed to a significant drop in transistor count from R600's ~720M. RV670 is made up of 666M transistors, and this includes the addition of UVD hardware, some power saving features, the necessary additions for DX 10.1 and the normal performance tuning we would expect from another iteration of the architecture.
Processing power remains unchanged from the R600; the RV670 features 320 stream processors, 16 texture units and 16 redner back-ends. Clock speeds have gone up slightly and memory speeds have increased tremendously to make up for the narrower memory bus.
The RV670 GPU is also fully PCI Express 2.0 compliant like NVIDIA's G92, the heart and soul of the GeForce 8800 GT.
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Locut0s - Thursday, November 15, 2007 - link
Well yes I know but the "cores" that they are using are extremely simplified, more so than I was thinking of. Instead I was thinking of each "core" as being able to perform most if not all of the steps in the rendering pipeline.Guuts - Thursday, November 15, 2007 - link
I think the simple answer is that in the CPU world, they hit a clockspeed wall due to thermal issues and had to change their design strategy to offer greater performance, which was to go to multiple cores.The GPU makers haven't reached this same wall yet, and it must be cheaper and/or easier to make one high-performing chip than redesigning for multi-GPU boards... though there are some boards that have 2 GPUs on it that act like SLI/Crossfire, but in a single board package.
I'm sure when the GPUs start suffering the same issues, we'll start seeing multi-core graphic cards, and I would assume that nvidia and AMD are already researching and planning for that.
dustinfrazier - Thursday, November 15, 2007 - link
Going on a year for Nvidia dominance and boy does it feel good. I bought my 8800gtx pair the first day they were available last year and never expected them to dominate this long. God I can't wait to see what comes out next for the enthusiasts. It get the feeling it is gonna rock! I really wanna see what both companies have up their sleeves as I am ready to retire my 8800s.I understand that these latest cards are great for the finances and good energy savers, but what does it matter if they already have a hard time keeping up with current next gen games at reasonable frame rates, 1920x1200 and above? What good does saving money do if all the games you purchase in 08 end up as nothing but a slide show? I guess I just want AMD to release a card that doesn't act like playing Crysis is equivalent to solving the meaning of life. Get on with it. The enthusiasts are ready to buy!
Gholam - Thursday, November 15, 2007 - link
For the reference, over here in Israel, 8800GT is promised to arrive next week - for approximately $380 + VAT (11.5%). For comparison, 8800GTS 640MB costs a bit over $400+VAT; 8800GTS 320MB used to cost in the low to mid 300s, but they're no longer available. I wonder when will 38xx get here, and at what price...abhaxus - Thursday, November 15, 2007 - link
let me just say that i love my 8800 gts. however, as a person stuck with a 939 athlon x2 @ 2.5 ghz, and wanting to upgrade to a quad core setup, I've been freaking out lately about what motherboard to buy, and the lack of new video cards has made that very difficult. If the 320mb gts dropped in price in relation to the new GT, I'd buy a 650i/680i board in a heartbeat and just SLI it up. But the fact that no innovation is going on has kept prices too high for too long. I've had this card since march and prices are actually higher now than when I bought it originally.At least intel isn't resting on their laurels the way nvidia has been. I want new cards... so the old ones get cheaper!
also if anyone wants to go really OT with a reply and tell me whether an Asus P5N32 SLI Plus would be a good choice to O/C a Q6600 to about 3.2 ghz and run 2 8800 GTS 320mb cards in SLI... let me know :)
wolfman3k5 - Thursday, November 15, 2007 - link
No, the P5N32SLI wouldn't be a good choice to overclock a Quad. Neither would be the Striker. The fact of the matter is that both this ASUS boards have a hard time putting out high FSB clock and sustain them with Quad Cores. You either go EVGA 680i (LT) if you want to retain the SLI capability, or I would suggest a P35 or X38 based motherboard.Just my 0.02C.
abhaxus - Thursday, November 15, 2007 - link
I've read that... but then I've also read on AT and that with current bios releases the asus boards are fine to around 360-400 FSB. I haven't O/C'ed an intel chip since the Celeron 300A so I am pulling my hair out trying to decide if it's worth it to plan for going SLI or just get a P35 board and stay with a single card.Anand Lal Shimpi - Thursday, November 15, 2007 - link
<font color=black>abhaxus - Thursday, November 15, 2007 - link
I apologize for breaking the comments... silly me for mentioning another site :)bupkus - Thursday, November 15, 2007 - link
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