ATI Radeon HD 4000 Series discussion

[DarkDisciple]

4870x2 should be *slightly* faster than two 4870s in CF, and blow away the 4850. It also has a decent chance of not suffering from micro stuttering because of how it is designed. (Uses shared memory instead of a bridge according to reports.) It will be a long time though before many games run at low enough FPS on 4870s in CF for the stuttering to be noticeable. Unless of course you are running at like 1900xsomething.

[waver_01]

4870x2 should be *slightly* faster than two 4870s in CF, and blow away the 4850. It also has a decent chance of not suffering from micro stuttering because of how it is designed. (Uses shared memory instead of a bridge according to reports.) It will be a long time though before many games run at low enough FPS on 4870s in CF for the stuttering to be noticeable. Unless of course you are running at like 1900xsomething.

I'm a bit worried about the power consumption though, 3870X2 is already at 200+W @ load, you'd expect 4870X2 to consume more

[AliG]

Yes, but also don't forget the core will probably be lower clocked (I mean the 4870 has more shaders than the 3870x2), and also the bridge chip will be shrunk down to 55nm, so it will consume more, but it will offer more power:power consumed than the 3870x2 imo (don't forget about the architecture improvements)

[GoldenTiger]

what about games? time will tell on this one. the HD4850's should be faster than the GTX280 but the 512mb on the 4850 concerns me considering i have seen games use more than 512mb already. i suspect the Crossfire HD4850 will win at lower resolutions and with lower AA levels. but crank that AA and the resolutions and maybe some AF and the GTX 280 should come out on top. but for the Price the HD4850's are going to be very attractive.

4870x2 should be *slightly* faster than two 4870s in CF, and blow away the 4850. It also has a decent chance of not suffering from micro stuttering because of how it is designed. (Uses shared memory instead of a bridge according to reports.) It will be a long time though before many games run at low enough FPS on 4870s in CF for the stuttering to be noticeable. Unless of course you are running at like 1900xsomething.

You guys really think the GDDR5 will make a huge differrence? The memory capacity I could see, but is the 4850 that bottlenecked? The 4850/4870 are identical but for the RAM and stock clocks as I understand it?

[bedlamite]

yep, identical but mems speeds and core clock.

[AliG]

Definitely the 4850 is going to be bottlenecked at the higher clocks, we're talking 800 shaders, the 2900xt might not have needed the bandwidth it had, but the 4850 will, that's the only explanation we have for how the 4870 will be 30% faster

[y2kbos]

You guys really think the GDDR5 will make a huge differrence? The memory capacity I could see, but is the 4850 that bottlenecked? The 4850/4870 are identical but for the RAM and stock clocks as I understand it?

When you overclock your card you see a difference?

[mascaras]

. It also has a decent chance of not suffering from micro stuttering because of how it is designed. (Uses shared memory instead of a bridge according to reports.)

source???



regards

[003]

I'm a bit worried about the power consumption though, 3870X2 is already at 200+W @ load, you'd expect 4870X2 to consume more

Then you are on the wrong forums, my friend.

This may be better suited for your needs:
http://www.silentpcreview.com/forums/

[perkam]

Then you are on the wrong forums, my friend.

This may be better suited for your needs:
http://www.silentpcreview.com/forums/

Well put

Perkam

[Extelleron]

I'm a bit worried about the power consumption though, 3870X2 is already at 200+W @ load, you'd expect 4870X2 to consume more

HD 4850 is way faster than HD 3870 in benchmarks, yet it consumes less power.

HD 4870 will consume just a bit more power than the 3870; the 4870 X2 will likely consume just a bit more than the 3870 X2. This time around 8 pin will likely be required, like on GTX 280 / 9800GX2. But I don't think power consumption will go up by much. Especially since 3870 X2 uses 1GB of GDDR3, 4870 X2 uses 1GB of GDDR5. Memory probably doesn't mean much, but it should make a small difference.

[perkam]

HD 4850 is way faster than HD 3870 in benchmarks, yet it consumes less power.

HD 4870 will consume just a bit more power than the 3870; the 4870 X2 will likely consume just a bit more than the 3870 X2. This time around 8 pin will likely be required, like on GTX 280 / 9800GX2. But I don't think power consumption will go up by much. Especially since 3870 X2 uses 1GB of GDDR3, 4870 X2 uses 1GB of GDDR5. Memory probably doesn't mean much, but it should make a small difference.

If the clocks end up being 775Mhz with 3.6ghz RAM, it will make an overall noticeable difference.

But the real reason people will buy the 4870 will be headroom. The 4850 will need voltmods or water to go beyond 725/2200, while the 4870 should scale to 825/4200 with ease.

Perkam

[waver_01]

Then you are on the wrong forums, my friend.

This may be better suited for your needs:
http://www.silentpcreview.com/forums/

No you guys are way too cool, I'll stay here

[Helmore]

No you guys guys are way too cool, I'll stay here

That's no wonder with all the LN2 action over here

[Xello]

Where are y'all getting the hard facts on the 4870 / 4870X2 from? Is this shared memory rumor still going around I'd like to know the 'multiple' reasons that the X2 will end up faster than 2 4870's in CF, all reasonable expectation and past experience (3870X2) says the opposite.

2x 4850 = 1GB GDDR3, GTX 280 = 1GB GDDR3

Perkam

Yeah, though unless DAAMIT have managed to overcome a basic limitation of these solutions you will still have 512mb of usable memory (frame buffer) on the crossfire setup, and also half the bus width of the 280.

[Helmore]

Where are y'all getting the hard facts on the 4870 / 4870X2 from? Is this shared memory rumor still going around I'd like to know the 'multiple' reasons that the X2 will end up faster than 2 4870's in CF, all reasonable expectation and past experience (3870X2) says the opposite.

There are no facts on this, these are just some remnants of what R700 was supposed to be. R700 was supposed to be a single chip that would fill in the low-end, mainstream and high-end market all at the same time. This would be done by just putting more of these chips on the same board, 1 chip would be for low-end, 2 chips for mainstream, 3 for performance and 4 for enthusiast. These were the plans for R700, at least the way ATI said it would be for R700, but this was about 3 years ago if not longer. This R700 has been scrapped, it might turn up later no-one knows, but you need these chips to cooperate properly and this will basically mean there will be shared memory (and more, more like each chip being a ring stop on the ring bus). The rumours of RV770X2 having shared memory stem from these early indications of what R700 was going to be and there are still hopes of this being true. Only AMD know though....

[conzymaher]

This is so frustrating! I just wanna be cryogenically frozen for 2 weeks and wake up to a review from a reputable site that compares:

4870
4850
GTX 260
9800 GTX
8800GT

/me sets alarm clock

[Xello]

There are no facts

Indeed, just reading more than a few posts with people talking as though there are.

[Cuthalu]

The 4850 will need voltmods or water to go beyond 725/2200, while the 4870 should scale to 825/4200 with ease.

Perkam

Why would you need a voltmod for an ati-card?

[Extelleron]

Why would you need a voltmod for an ati-card?

I don't know if these cards will support voltage increases via software. HD 2900 did I believe, but HD 3800 did not. ATI used to allow it, but perhaps AMD has other ideas.

Also ATi Tool would have to be updated to support it, AFAIK that's the only software that changes GPU voltage, right? You could edit the BIOS I suppose.

[GAR]

OK, so release date for these are June 25th??? for both 4870/50

[Papu]

i guess those rumors about it hitting 1ghz on air were lies

[Extelleron]

i guess those rumors about it hitting 1ghz on air were lies

Nobody has really overclocked a HD 4850 yet as the only app supporting it is CCC and it only allows up to 700MHz core. Jimmyz says it hits 700MHz without any problem. 1GHz is probably far fetched, but I would think 750-800MHz would not be out of the question. For the 4870, maybe 900MHz+ will be a possibility.

[MpG]

I think the 1 Ghz rumours came from people trying to reverse engineering the claimed flop counts based on only 480 shaders.

[adamsleath]

This is so frustrating! I just wanna be cryogenically frozen for 2 weeks and wake up to a review from a reputable site that compares:

4870
4850
GTX 260
9800 GTX
8800GT

/me sets alarm clock

been there done that..this is an automated response.
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