Power Consumption

Life is not as affordable as it used to be, and items such as gasoline, natural gas, and electricity all top the list of resources which have exploded in price over the past few years. Add to this the limit of non-renewable resources compared to current demands, and you can see that the prices are only going to get worse. Planet Earth is needs our help, and needs it badly. With forests becoming barren of vegetation and snow capped poles quickly turning brown, the technology industry has a new attitude towards suddenly becoming "green". I'll spare you the powerful marketing hype that I get from various manufacturers every day, and get right to the point: your computer hasn't been doing much to help save energy... at least up until now.

To measure isolated video card power consumption, Benchmark Reviews uses the Kill-A-Watt EZ (model P4460) power meter made by P3 International. A baseline test is taken without a video card installed inside our computer system, which is allowed to boot into Windows and rest idle at the login screen before power consumption is recorded. Once the baseline reading has been taken, the graphics card is installed and the system is again booted into Windows and left idle at the login screen. Our final loaded power consumption reading is taken with the video card running a stress test using FurMark. Below is a chart with the isolated video card power consumption (not system total) displayed in Watts for each specified test product:

The Radeon HD 4870 X2 is clearly no stranger to high power bills based on the fact that it tops our chart for power consumption under load. The story gets worse for the Revolution 700 when you take idle readings into account, because Palit somehow decided to skip power conservation engineering and gave low 2D mode the full brunt of low-power 3D mode instead. As a result the Palit Radeon HD 4870 X2 video card drinks power at idle, and gulps down the watts at a faster pace than the reference 4870 X2 and Radeon HD 4870 CrossFireX set under maximum power conditions. As a testament to the Revolutions' appetite, Palit's 4870 X2 needs an 8- and 6-pin power source compared to the reference Radeon HD 4870 X2 that requires (only) two six-pin PCI-Express power connections. This may leave some middle-market enthusiasts and lower-end gamers in search of a new power supply force feed the Palit Radeon HD 4870 X2 the power it needs.

Most enthusiasts make the mistake of associating a smaller die process with an improved power efficiency. Clearly, the downside to the 55 nm RV770 GPU is it's lack of energy efficient operation. Putting two together on the same PCB doesn't double the consumption of a single Radeon HD 4870, but it sure does try. The power consumption measured under full load doesn't match the performance, but it certainly matched heat output. The idle power draw is extremely high, which is uncommon since emphasis is usually placed on idle/standby mode efficiency and conservation.

Taken as a whole the idle stand-by power consumption is pretty unforgivable, especially since this the condition your equipment will be in the majority of the time. While loaded power consumption is the highest we've ever seen, the price paid to your utility company for gaming would be about the same with just about any other video card. Once upon a time, the computer and gaming consoles seemed like an inexpensive alternative to arcade gaming... but that was before energy costs soared through the roof.

Revolution 700 Heat Output

Normally I would go into great detail and illustrate where a video card heats up the integrated components with use of a non-contact IR thermometer. However Palit kept a short leash on the Radeon 4870 X2 they loaned me, and it was sent back on its way to the next editor only a few days after first receiving it. No worries... I did what I could. The ambient room temperature was steady at exactly 18.0°C and the inner-case temperature hovered around 30°C. To begin my testing, I used GPU-Z to record temperatures at idle and then switched to Furmark for high-power 3D mode.

At idle the Palit Radeon HD 4870 X2 recorded an extremely cool 39°C (compared to 76°C for the reference design). Once I began to use 3D mode (which asks for another 220W) for roughly twenty minutes, the Palit Radeon HD 4870 X2 didn't waste any time before the heated air was spilling out the sides. At full load, the twin RV770's produced an impressively low operating temperature of 76°C (compared to the reference design that produced 92°C).

Please continue to the review conclusion in the next section, where I share my final thoughts on the RV770 graphics processor and give my opinion of the new Radeon HD 4800-series product offerings.

<< Previous Page - Next Page >>