Technical Differences between 4870 vs 4890

[EastCoasthandle]

This thread was created to show the differences between the 4870 and 4890 based on the information I've read about. Since we know this isn't a 4870 that was simply overclocked there should be a better understanding of what is different between the 2.

What's different about the 4890's GPU?
So far, what I found out is that the GPU has a de-coupling ring around it's edge. This de-coupling ring adds 3million more transistors making the total transistor count 959 million (up from 956 million). From the video interview the RV790 is a new ASIC. So is it a new chip? Physically, yes it is based on the improvements made but there is no logic design changes.

The above pic should provide you with some ideas of what was changed.




What's different about the video card itself?
Below is a pic showing both the 4870 and 4890. You can clearly see that there is some differences between the 2.

4870 Heat Sink Design

4890 Heat Sink Design

Backside of the 4870

Backside of the 4890

4870 VRMs 3+2. To the right is the controller.

4890 2 VRMs 5+2. To the right are 2 two Volterra VT1165MF controllers.

Two parallel SMD inductors are used for 5-phase GPU power supply: 3-phase CPLA-3-50 and 2-phase Pulse PA1312NL. Besides, the MOSFET power chips are of different models. Four of them are VT1165SF which cost $3.5 each, and the remaining one is VT1195SF. They all feature Chip Scale Package, built-in MOSFET and driver chip. VT1195SF is capable of delivering maximum current of 40A, and VT1165SF can deliver Max. 30A current.

That is to say, Radeon HD 4890 can deliver Max. 160A current to GPU, compared with Max. 120A on HD 4870, which lays the groundwork for high clocks and great overclocking potential for Radeon HD 4890.

source

4870

4890 Volterra VT1165 controllers

Radeon HD 4890 has employed two Volterra VT1165MF controllers just like Radeon HD 2900XT. We believe both of the two controllers on HD 4890 are prepared for GPU power supply, as the inductances used in 5-phase power circuit are not exactly the same, and VT242WF chips for memory power supply already has function of controlling IC. But the case is different when it comes to Radeon HD 2900XT: One of the two Volterra VT1165MF controller serves GPU power supply, and the other one serves memory power supply.

Theoretically, one VT1165MF is capable of managing up to 6-phase power supply. One of the two PWM chips is possibly designed to control 3-phase circuit, and the other controls 2-phase so as to enhance the GPU power supply. Only one single VT1165MF controller costs about $3, which increases the cost of the whole card.

source

4870 2 phase memory power

4890 CSP VT242WF

Radeon HD 4890 employs two CSP VT242WF chips (also from Volterra) for the 2-phase memory power supply to deliver more than 20A current, much more than the maximum current required by memory (about 12A). VT242WF has intergrated MOSFET and driver IC as well as control IC, so it costs $5, more expensive than VT1000 Series. Besides, Pulse ceramic SMD inductor is also adopted which provides better performance.

Radeon HD 4890 features multi-layer ceramic capacitors which are usually seen at the rear side of Intel’s CPUs. They’re capable of delivering steady performance and heat-resistant ability. Three Japanese solid capacitors can be found on the card as well.

source

Overall IMO, the power design of the 4890 appears to be better then the 4870. Only time will tell how well performance gets as drivers mature.

Please note that this post maybe edited if more information becomes available.

 

[grunt_408]

informative thanks for this info.

 

[Blacksniper87]

hmm just a question but didn't some site say that these cards are somewhat unstable as in they crash??

 

[EastCoasthandle]

Blacksniper87,

I haven't read any reports of such a problem at stock clocks. As for overclocking is concerned the rules are no different then any other video card. You just have to find what's stable based on your setup, etc.

 

[Darknova]

Very informative, still doesn't make me want to run out and replace my 4870 though...

 

[btarunr]

Some info, from AMD EU: The interview only starts off in German, but continues in English: http://www.youtube.com/watch?v=9gyzY_-42N0

 

[DrPepper]

Excellent find now we can't argue that it is a simply high binned gpu.

 

[EastCoasthandle]

Excellent find now we can't argue that it is a simply high binned gpu.

What will also be interesting is to see what changes are made to the video card itself once we see 8+6 pin 4890 OC editions. Hopefully before the end of this month.

 

[DrPepper]

What will also be interesting is to see what changes are made to the video card itself once we see 8+6 pin 4890 OC editions. Hopefully before the end of this month.

I'm curious about the non reference versions.

 

[jaydeejohn]

Thanks, its good having all the info in one post. Im hoping they release special oceed versions as well Crank em up!!

 

[EastCoasthandle]

Hopefully, we can get a technical explanation of these 8+6 pin video cards like we've seen with the 4890. That way we can have a comparison between them.

 

[sapetto]

Great card but it think its stupid when the card is selling and theres no official driver for it :shadedshu

 

[wiak]

Great card but it think its stupid when the card is selling and theres no official driver for it :shadedshu

check CD?

 

[LuxZg]

Hey EastCoast, nice comparision. Any way to obtain good shots of ASUS HD4890 "voltage tweak" edition? It can go up to 1.45V by using software (Smart Doctor). If there is no hardware changes, that would mean that any reference HD4890 can be soft-moded to get some extra juice when overclocking.

I'll try to find a picture, but I'm not much into power regulation chips, so I wouldn't know much

 

[EastCoasthandle]

Hey EastCoast, nice comparision. Any way to obtain good shots of ASUS HD4890 "voltage tweak" edition? It can go up to 1.45V by using software (Smart Doctor). If there is no hardware changes, that would mean that any reference HD4890 can be soft-moded to get some extra juice when overclocking.

I'll try to find a picture, but I'm not much into power regulation chips, so I wouldn't know much

We really have to wait until the product is released first to see what the final version will look like. Hopefully by then better photos will surface.

 

[ShadowFold]

ASUS has software for the 4890's I thought?

 

[EastCoasthandle]

ASUS has software for the 4890's I thought?

There is another 4890 that's suppose to be introduced by Asus.

 

[LuxZg]

Here is a pretty good picture of BACKSIDE of the "Voltage Tweak" card.

http://www.phoronix.net/image.php?id=amd_radeon_hd4890&image=amd_rv790_pcb_lrg

Voltage tweaks already work on this card, so I don't think that the cards in shops will be any diffrent. and the card is already selling, so even more the reason to believe that there won't be any major changes.

EDIT: Found it! Several good pictures of whole card, including naked picture, and a nice close-up of power regulation as well
http://www.overclock3d.net/reviews.php?/gpu_displays/asus_eah_4890_1gb_ddr5_pcie_graphics_card/2
(btw, next page of review clearly says that they could overclock it to 975MHz, but after they brought up voltages with Smart Doctor they were able to hit 1GHz)

And another pic, but again backside-only :/ I'll leave it as it's good quality
http://www.driverheaven.net/reviewimages/radeon4890_and_gtx275/asus_4.jpg

Can anyone spot any differences from reference cards? I'm looking at them at the moment..

EDIT2: I really don't see any differences except that smaller PULSE chips have SAME "model number" but under it in EastCoast's picture it says "0907-S CHINA" and on ASUS card it's "0906-S CHINA". But since above number is exactly the same, is this maybe year(09) and week(07) of production? If it is, than these cards look to be the same as all reference cards. Which in turn means that:
a) you can take ASUS BIOS and flash any other card, and Smart Doctor should work (worked on HD4870)
b) take your BIOS and just change markings so it says that it's ASUS board (also worked on HD4870)
c) make software that does it

But let's first have few more people (that are more expirienced than me) take a look at these pictures..

 

[EastCoasthandle]

Luxzg, that's the current Asus video card. There is suppose to be another version AKA OC edition or whatever they call it.

Again if this does surface we have to wait for retail version. Hopefully by then we have better pics.

 

[LuxZg]

Oh, that's a different version alright. But I don't see how it makes things different regarding voltage changes. Current ASUS card, which was seeded to reviewers, and which (by the looks of it) is same as reference card - CAN change voltage up to 1.45V through software.

This would mean that any reference card can do the same.

Am I missing something?

 

[Jeffredo]

Nice refresh.

 

[EastCoasthandle]

Nice refresh.

I agree I've noticed that people are buy these cards.

 

[nafets]

Oh, that's a different version alright. But I don't see how it makes things different regarding voltage changes. Current ASUS card, which was seeded to reviewers, and which (by the looks of it) is same as reference card - CAN change voltage up to 1.45V through software.

This would mean that any reference card can do the same.

Am I missing something?

Sigh.

They're all the same right now, Lux. So they can all be software voltage adjusted. I've studied 30-40 HD4890 PCB pics, and I have yet to see any deviation in current board design/layout/components.

Asus is supplying the voltage software with their cards (subject to the stipulations you listed), that's all. Everything is so darn new and fresh, so it's hard to get concrete answers. People are busy OC'ing the turd out of their HD4890s and/or running thousands of 3DMark runs. The answers will come, slowly but surely.

With proper Rivatuner support, the functionality is similar to Asus's SmartDoc software.

The black PCB Asus card pictured above is for their upcoming HD4890 "Matrix" model, most likely with a non-reference "Matrix" cooler. With an added Fujitsu voltage regulator and 8-pin PCI-E connector replacing one of the 6-pin PCI-E connectors, it should allow for even better overclocking with greater stability.

 

[purecain]

anyone care to upload a asus 4890 bios.... and voltage tweak....
thanks in advance....

 

[DrPepper]

anyone care to upload a asus 4890 bios.... and voltage tweak....
thanks in advance....

If its for a 4870 it will likely brick the card Unless your a pioneer.