AMD’s Radeon HD 5850: The Other Shoe Drops
by Ryan Smith on September 30, 2009 12:00 AM EST- Posted in
- GPUs
AMD’s Radeon HD 5850: The Other Shoe Drops
“For those of you looking for the above and a repeat of the RV770/GT200 launch where prices will go into a free fall, you’re going to come away disappointed. That task will fall upon the 5850, and we’re looking forward to reviewing it as soon as we can.”
-From our Radeon HD 5870 Review
Today the other shoe drops, with AMD launching the 5870’s companion card: the slightly pared down 5850. It’s the same Cypress core that we saw on the 5870 with the same features: DX11, Eyefinity, angle-independent anisotropic filtering, HDMI bitstreaming, and supersample anti-aliasing. The only difference between the two is performance and power – the 5850 is a bit slower, and a bit less power hungry. If by any chance you’ve missed our Radeon HD 5870 review, please check it out; it goes in to full detail on what AMD is bringing to the table with Cypress and the HD 5800 series.
| ATI Radeon HD 5870 | ATI Radeon HD 5850 | ATI Radeon HD 4890 | ATI Radeon HD 4870 | |
| Stream Processors | 1600 | 1440 | 800 | 800 |
| Texture Units | 80 | 72 | 40 | 40 |
| ROPs | 32 | 32 | 16 | 16 |
| Core Clock | 850MHz | 725MHz | 850MHz | 750MHz |
| Memory Clock | 1.2GHz (4.8GHz data rate) GDDR5 | 1GHz (4GHz data rate) GDDR5 | 975MHz (3900MHz data rate) GDDR5 | 900MHz (3600MHz data rate) GDDR5 |
| Memory Bus Width | 256-bit | 256-bit | 256-bit | 256-bit |
| Frame Buffer | 1GB | 1GB | 1GB | 1GB |
| Transistor Count | 2.15B | 2.15B | 959M | 956M |
| TDP | 188W | 151W | 190W | 150W |
| Manufacturing Process | TSMC 40nm | TSMC 40nm | TSMC 55nm | TSMC 55nm |
| Price Point | $379 | $259 | ~$180 | ~$160 |
AMD updated the specs on the 5850 at the last moment when it comes to power. Idle power usage hasn’t changed, but the final parts are now specified for 151W load power, versus the 160W originally given to us, and 188W on the 5870. So for the power-conscious out there, the 5850 offers a load power reduction in lockstep with its performance reduction.
As compared to the 5870, AMD has disabled two of the SIMDs and reduced the core clock from 850MHz to 725Mhz. This is roughly a 15% drop in clock speed and a 10% reduction in SIMD capacity, for a combined theoretical performance difference of 23%. Meanwhile the memory clock has been dropped from 1.2GHz to 1GHz, for a 17% overall reduction. Notably the ROP count has not been reduced, so the 5850 doesn’t lose as much rasterizing power as it does everything else, once again being 15% due to the drop in clock speed.
With the reduction in power usage, AMD was able to squeeze Cypress in to a slightly smaller package for the 5850. The 5850 lobs off an inch in length compared to the 5870, which will make it easier to fit in to cramped cases. However the power connectors have also been moved to the rear of the card, so in practice the space savings won’t be as great. Otherwise the 5850 is a slightly smaller 5870, using the same sheathed cooler design as the 5870, sans the backplate.
Port-side, the card is also unchanged from the 5870. 2 DVI ports, 1 HDMI port, and 1 DisplayPort adorn the card, giving the card the ability to drive 2 TMDS displays (HDMI/DVI), and a DisplayPort. As a reminder, the DisplayPort can be used to drive a 3rd TMDS display, but only with an active (powered) adapter, which right now still run at over $100.
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Seramics - Thursday, October 1, 2009 - link
HD5800 series is bandwidth limited. The 5850 being less severe than 5870. 5850 has about 77% computing power and about 83% of memory bandwidth of 5870. So normally, 5850 should perform about 77% as fast as 5870 but it wasnt the case here. If you calculate all the benchmarks performance at all resolution, its surprisingly consistent, 5850 is always around 82-85% performance of 5870. Never did it drop to below 80% performance level, let alone coming close to 77% which is where it should be. Different game has different bandwidth requirement and there's fluctuation in percentage improvement from 4800 series to 5800 series. It unstable but 5870 for eg rarely doubles 4870, let alone 4890. So in the end, its not parallelization or scaling problems, nor was it geometry or vertex limitation (possible but less likely), it is indeed the 5800 series being limited in performance due to restricted memory bandwidth. Those of you who has 5800 cards, overclock the memory and check the scaling and you'll see wht i mean.silverblue - Thursday, October 1, 2009 - link
Overclocking the RAM is one idea, adding more RAM is another, however it remains to be seen whether ATI will introduce a wider bus for any higher spec models.The situation is a little different to the 4830 - 4850 comparison whereby the 4830 had slightly lower clocks but only 640 SPs enabled instead of the full 800, however in the end the performance difference wasn't very large so the lack of shaders didn't cripple the 4830 too much.
Jamahl - Thursday, October 1, 2009 - link
I'm not convinced about that, many games run on 3 30" lcd's with no issues.More likely is the games aren't pushing the cards to their maximums, that is why you aren't getting the full effect. We will find out for sure when the 2gb version is released.
Seramics - Thursday, October 1, 2009 - link
If u cant see it thats ur problem, to say games arent pushing it is noobish, 1gb is still plentiful for today's games, memory buffer was nv an issue as long as its 1gb. well in the end u will see faster ram outperforming ur 2gb version. Very amazing to see many people still cant figure out the main reasons of 5870's underperformance.It is still a decent card and offer many features and definitely a better performance to price ratio card than GTX 285. But it is underperforming. Not living up to its nex gen architecture prowess. Unless GT300 screw up, it can easily outperform 5870 when its out. If AMD came out quickly with 5890, they will be wise to significantly bump up the GDDR5 speed as it is unlikely they will go with higher than 256bit design due to their "sweet spot" small die strategy.
Jamahl - Thursday, October 1, 2009 - link
Wait...you really think that you have it figured and ATI didn't realise it? You truly believe that ATI would lower the performance of the card instead of just strapping on a 384 bus?No. Any bandwidth issues only exist in your head. Didn't you say that different games have different bandwith requirements?
Jamahl - Thursday, October 1, 2009 - link
Any ideas what is going on here with that?loverboy - Thursday, October 1, 2009 - link
I would really love to know how these games run with this added xtra.One of my main reasons for upgrading would be to play WOW on three screens (most likely in window mode).
Would it be possible to add this benchmark in the future, with the most obvious config being 3 screens in 2560/1920/1680
yolt - Wednesday, September 30, 2009 - link
I'm looking to pick one of these up relatively quickly. My question is there really a difference in which vendor I purchase from (HIS, Powercolor, Diamond, XFX, etc). I know many offer varying warranties, but if they offer the same clock speeds, what else is there? I guess I'm looking for the most reputable brand since I won't be waiting for too many specific reviews before purchasing one. Any help is appreciated.ThePooBurner - Wednesday, September 30, 2009 - link
Where and under what conditions/server load do you test the frame rate in WoW? I've played for years and with my 4850 i can get 100fps in the game if i am in the right spot when no one else is in the zone. Knowing when and where you do you frame rate tests for WoW would help to put it into context.Ryan Smith - Thursday, October 1, 2009 - link
This is from Anand:"...our test isn't representative of worst case performance - it uses a very, very light server load, unfortunately in my testing I found it nearly impossible to get a repeatable worst case test scenario while testing multiple graphics cards.
I've also found that frame rate on WoW is actually more a function of server load than GPU load, it doesn't have to do with the number of people on the screen, rather the number of people on the server :)
What our test does is simply measures which GPU (or CPU) is going to be best for WoW performance. The overall performance in the game is going to be determined by a number of factors and when it comes to WoW, server load is a huge component."