Sapphire Radeon HD 6670 Ultimate Video Card Review

Product: Sapphire Radeon HD 6670 Ultimate
Company: Sapphire
Author: James Prior
Editor: Pete Vagiakos
Date: July 29th, 2011

Test Configuration & Dual Graphics

Performance Testing

For today's testing we used our new AMD A-series platform, recently tested here and as detailed below:

Test Platform

Component Specification
Mainboard Gigabyte A75M-UD2H
Processor A8-3850
Graphics Card APU HD 6550D
  Sapphire HD 6670 Ultimate
  Sapphire HD 6770 VaporX
Memory 2x2GB Mushkin Blackline PC-16000 @ DDR3-1600
Audio Realtek ALC889
PSU Zalman ZM600-HP
Case CoolerMaster HAF 922
Storage Corsair F120 + Seagate 7200.11 1TB
Heatsink/Fan Sunbeamtech Core-Contact Freezer
Display Dell P2210H
Operating System Windows 7 32-bit Ultimate SP1
Driver Catalyst 11.6b hotfix + CAP 11.6 #2

Based on our findings in our initial look at the Lynx platform, we're running DDR3-1600 RAM as that offers the best bang/buck for performance and is most suited to the ethos of building a Lynx platform. For our measurements, we're going to take a look at the card when working solo, when it's combined with the A8-3850 APU in Dual Graphics mode, and against the Radeon HD 6770. At $105USD the Sapphire HD 6670 Ultimate is pretty close in price to the Radeon HD 6770, but the Radeon HD 6670 can CrossfireX with the Radeon HD 6550D inside the A8-3850 APU.

Dual Graphics

Dual Graphics Options

When AMD moved the multi-GPU component out of the main driver, they opened up the compatibility matrices for CrossfireX. Theoretically, AMD can enable mGPU a 9700Pro with a HD 5870; you don't, for obvious reasons.

The obvious corollary to that is any restrictions on Dual Graphics or CrossfireX is not 'can't do it, different architectures make it impossible for the driver' but more likely 'it doesn't work well' or 'we haven't tested it yet so we aren't going to permit it while we can't respond adequately to the problems yet' (of which a subset would be 'we don't think more than a very small fraction of a percent of users in the world want to do that, so we'd rather spend the resources on making games run better for everybody else.').

Llano could be run in dual graphics with a Juniper or Barts card, but it isn't; it's not a configuration that will get huge sales and the effort to optimize for that case isn't going to be worth it (yet). Officially, AMD states that for optimal performance the discrete GPU performance should be the same or up to 2x the performance of the APU graphics. AMD Dual Graphics (a Windows 7 exclusive feature) is not available with discrete graphics performance below 0.5x or above 3x, compared to the APU graphics.

Trinity, the 2012 APU with promises of 50% more performance than Llano is supposedly featuring a VLIW-4 GPU architecture. For Dual Graphics CrossfireX with next generation cards, this means it's not a requirement that the mainstream cards be VLIW-4 but it's possible they could be VLIW-5 or GCN. What it comes down to, is does it make sense to push the rest of the lineup as GCN, from the entry level through to the top end, or is it better to stagger the next gen entry?

To consider that point, let's recap the first two DirectX 11 generations. Evergreen debuted with 4 ASIC's into six product lines (Cedar - 5400; Redwood - 5500,5600; Juniper - 5700; Cypress - 5800, 5900).

Northern Islands brought four new ASIC's, but only one of them was new architecture, and a fifth was a carry-over from Evergreen. Five ASIC's in total became six discrete card product lines (Cedar becomes Caicos - 6400; Redwood becomes Turks - 6500, 6600; Juniper gets a UVD firmware update - 6700; Cypress becomes Barts - 6800; Cayman is the new VLIW-4 arch - 6900). Ontario and Zacate APU's had a tweaked Cedar GPU core (that's 7 GPU cores). Llano APU's feature tweaked Redwood GPU architecture variants called Sumo (dingdingding - 8!), and mGPU compatible with Caicos and Turks mobility variants.

Now we know what the driver can do, it's obvious that the lack of ability to configure mGPU between Cedar and Caicos; Redwood and Turks; Cypress and Barts; is a little bit because of fear of cannibalization of new cards and mostly because the possible return isn't large enough to be worth it - mGPU is a low volume area, and most people buy the best performance new single GPU rather than go for a class down part to double up power, heat and noise. The possible exceptions would be Cypress Pro and Barts XT (6870 + 5850), or Cypress XT and Cayman Pro (6950 + 5870), as those combinations might have been very attractive to those owners of the previous generation at the time the new generation launched.

Dual Graphics Branding

AMD have made it possible to CrossfireX the AMD A-series APU's with the Turks based GPU's, of which the Sapphire Radeon HD 6670 Ultimate is one. For our testing we compared the discrete performance of the HD 6670 to the HD 6770, and Dual Graphics with the HD 6670 as primary GPU. Dual Graphics of the AMD HD 6550D and HD 6670 is known as Radeon HD 6690D2. In our previous look at Llano we noted that Dual Graphics with the APU graphics as primary means the improvements of the Turks tweaks are missing. With then newer Gigabyte BIOS we can now run with the Sumo GPU core disabled, and the Sumo GPU as secondary to the Turks discrete GPU in Dual Graphics mode. The only configuration still not working that we wanted to test on the Gigabyte board was CrossfireX between two dGPU Turks boards.

Below you can see a comparison of the graphics cards tested today:

  APU HD 6550D Sapphire HD 6670 Sapphire HD 6770
GPU Core 32nm Sumo 40nm Turks XT 40nm Juniper XT
Engine Clock 600MHz 800MHz 860MHz
Radeon Cores (SIMD) 400 (5) 480 (6) 800 (10)
Texture Units 20 24 40
ROP's 8 8 16
Memory Capacity upto 1GB 1GB 1GB
Memory Type System DDR3 GDDR5 GDDR5
Memory Bus 64-bit 128-bit 128-bit
Memory Speed System 1GHz / 4Gbps QDR 1.2Ghz / 4.6Gbps QDR
UVD 3 3 2.2
Outputs DVI/VGA/HDMI 1.4a/DP 1.1 DVI/DP 1.2/HDMI 1.4a DVI/DP 1.1/HDMI 1.4a
Multi-Display Dual, or DL-DVI Eyefinity 3 Eyefinity 3