HIS Radeon HD 7950 IceQ Turbo Video Card Review



Product: HIS Radeon HD 7950 IceQ Turbo Video Card
Company: HIS
Author: James Prior
Editor: Charles Oliver
Date: September 26th, 2012

Test system & Overclocking

Our test platform is as detailed below:

Test Platform

Component Specification
Mainboard ASUS P8P67 WS Revolution
Processor Core i7-2600K [4.7GHz]
Graphics Card HIS Radeon HD 7950 IceQ Turbo
  AMD Radeon HD 7950
  AMD Radeon HD 7950 Boost
Memory 2x4GB Crucial DDR3-1333 @ DDR3-1600 9-9-9-25 2T
Audio Realtek ALC892
PSU Corsair HX850
Case CoolerMaster HAF X w/Adt'l 200mm Top Exhaust
Storage Drives OCZ Vertex 2 120GB
  Western Digital Caviar Black 1TB
Heatsink/Fan Noctua NH-D14
Display 3x Dell P2210H
Operating System Windows 7 64-bit Ultimate SP1
Driver Catalyst 12.8 CAP 2
HIS Radeon HD 7950 IceQ Turbo vs. Reference 7950

Product Specification Comparison

  HD 7950 Ref HIS 7950 IceQ Turbo HD 7950 Boost
SEP (USD) $319 $349 (-$20MIR) $319
Engine Clock 800MHz 900MHz 850MHz/925MHz
Cores 1792 1792 1792
Architecture Tahiti GCN Tahiti GCN Tahiti GCN
Memory Capacity 3GB 3GB 3GB
Memory Speed 1250MHz / 5Gbps QDR 1250MHz / 5Gbps QDR 1250MHz / 5Gbps QDR
Bus Width 384-bit 384-bit 384-bit
Power [Idle/Limit] <3W / 200W <3W / 200W <3W / 200W

Boost

In August, AMD updated the AMD Radeon HD 7950 with the Boost feature to match their new flagship card, the HD 7970 GHz Edition. This was delivered via a combination of AMD Catalyst driver and card firmware update, delivered to AMD's Add-In Board (AIB) partners but also released to the public with one caveat - it only works on reference AMD design cards. As our AMD Radeon HD 7950 is an engineering sample from AMD itself, the update method worked like a charm; run the updater, reboot, reinstall drivers and away we go. Courtesy of AMD's dual-BIOS design, we can switch from reference design 7950 to Boost 7950 with the flick of a switch and a reboot. The Boost BIOS takes advantage of what AMD has learned since launch and uses AMD's PowerTune feature to closely monitor the card workload. PowerTune was designed to stop the card exceeding a specified thermal design point (TDP), a crucial feature for consumers and system builders alike to protect their purchase and maximize card life.

7950 Boost update

For good or ill, AMD remains conservative in their PowerTune limits, typically setting it where it only engages for long runs of what IHVs term 'Power Virus' applications like Furmark, OCCT etc. These applications are designed to light up as much silicon as possible, producing the most heat the design is capable of as a stress test to verify stability. Overclockers have long used applications like these to prove card stability, as in theory the 'power virus' applications stress the card harder than it will ever see in day to day use. This causes a problem for card makers, as it's a non-use case workload being used to describe aspects of the card - purchase decisions are being made based on information that doesn't apply to how they'll use it. By throttling the power virus apps, the intent is keep full performance in games and compute applications at time same time as preventing damage to the card for outlier cases.

PowerTune technology takes measurements of the physical card and the running workload to create an instant snapshot of the power profile of the card. If that snapshot looks to exceed the TDP of the product, PowerTune adjusts the card core clock speed to stay within it's power boundaries. This is not a hard shunt to idle clock but a very granular stepping as PowerTune offers upto 256 levels of clock speed with multiple voltage levels. In the Boost BIOS, the card runs the second from top state instead of the topmost one. For a reference Tahiti Pro, the 800MHz engine clock at ~1.087v is increased to 850MHz. The new top most state is 925Mhz engine clock at 1.25v. This Boost level is only used when the application workload is permitted in the board power profile; 200W in the case of Tahiti Pro. Using the new Boost BIOS with AMD Catalyst 12.7beta or newer, reference design HD 7950 cards get a free performance boost with no extra power used. The new BIOS also increases the limits of AMD's built in Overdrive GPU overclocking feature, permitting an adjustment of the boost clock to 1200Mhz.

Reference
Boost

AMD's provided firmware updater refused to run on the HIS Radeon HD 7950, failing to install the BIOS. We then used ATI Win Flash to save from our updated reference card and flash the firmware to the HIS card, but when rebooting after receiving successful flash message, the system failed to POST. We recovered by powering off and selecting the backup, write protected original BIOS and then trying again. Fortunately we had taken an image of the original BIOS before overwritting it, although we could have easily saved the backup BIOS and restored it. Restoring is simple, but involves touching the card while everything is powered on - you have to move the BIOS switch back to the unprotected position before executing the flash. Take precautions, an accidental flash or unprotected discharge could result in improperly operating firmware or additional hardware costs.

Overclocking

We used HIS iTurbo v1.2.1 for our overclocking endeavours, downloaded from HIS' website. This application gives us control over engine clocks, engine voltage, powertune level, memory clocks and memory voltage. We found that when used with the reference HD 7950 and HIS 7950, voltage was capped at 1.2v, but with the Boost firmware installed, iTurbo allowed well over 1.3v to selected on the reference design, indicating that the level of voltage adjustment permitted is constrained by a firmware setting.

  Reference 7950 HIS IceQ Turbo Boost 7950
Engine Clock 1085MHz 1175MHz 1200MHz
Engine Voltage 1.156v 1.156v 1.262
Memory Speed 1800MHz/7.2Gbps 1800MHz/7.2Gbps 1800Mhz/7.2Gbps
Memory Voltage 1.6v [default] 1.625v 1.6v [default]
HIS 7950 IceQ Turbo
HIS IceQ Turbo OverClock

As you can see, the 1.2v limit hampers both the reference and HIS 7950's, with near identical results. Interestingly the reference design card requires no extra voltage to hit 1800MHz/7.2Gbps on the memory where the HIS card needed a little nudge. For our final overclock settings we settled on 1085Mhz engine / 1775MHz for the HIS card and 1200MHz / 1800MHz for the Boost configured reference 7950. The HIS Radeon HD 7950 overclocks by 20.5% on the engine and 42% on the memory. We settled on 1775 as this speed didn't need any extra memory voltage, and both cards could do it for our CrossFireX testing. Overclocking under Crossfire requires the Ultra Low Power State function to be disabled, something that can be done from the iTurbo application. This disables the GCN architecture Zero Core Power feature, and increases idle power use.

7950 CrossfireX

Our final testing configuration is:

  Ref 7950 Boost 7950 7950 OC HIS IceQ Turbo HIS IceQ Turbo OC
Engine Clock 800MHz 850MHz [Boost 925Mhz] 1200MHz 900Mhz 1085MHz
Memory Speed 1250MHz / 5Gbps 1250MHz / 5Gbps 1800MHz / 7.2Gbps 1250MHz / 5Gbps 1775Mhz / 7.1Gbps