150W TDP is 150W TDP, the GPU may be cooler but the heat is still being produced. If you overclock the GPU the heat output may be even worse and besides this, the GPU is designed to run hot to prevent heat cycling (one of the main causes of the Nvidia GPU failures). Just because people think that a hot GPU is a problem doesn't mean it actually is.

ATX specification has a rear cooling fan just above the output of the GPU by design so most of the heat goes straight out of the case anyway. This isn't really a problem unless you're using multiple GPUs where radiated heat can compound the issue further even with a dual slot card. Remember a 4850 uses similar wattage to an entire Falcon Xbox 360 and thats on top of other componentry inside the case. Add a 2nd and you've got quite a heat problem.

There's a very low ceiling when it comes to overclocking with the R700 because of the heat.

Like any other processor, lowering the core temps is conducive to running at higher frequencies while maintaining stability. You wouldn't make the same argument about running an overclocked CPU with a stock cooler vs. a more efficient aftermarket cooler, so why would you think the R700 is any different?

Mainly because few regular PC users look into aftermarket VGA cooling solutions. In most cases, it isn't necessary.

But if I had the option between running a GPU at 70 idle or 40 idle, that's kind of a no-brainer if OC performance was priority one over any related additional costs. Running a pair of R700s in Crossfire config is best done with cases that place VGA cards between a 120mm intake and 120mm exhaust fans in addition to the stock or aftermarket cooler.

A stock 4870x2 has no temp problems when installed in an appropriate case, and it is not much more than a pair of R700 GPUs with 2GB worth of memory modules on a single card. The inside of an Antec 900 with 5 fans isn't even slightly warm.

Does anyone know how to set to set it to accelerated decoding? I bought the Geforce 9800GT so I can play HD videos smoothly with no stutter but it still doesn't play smoothly. Been told I have to set something to accelerated decoding so that only the graphics card does the work but I have no idea how to do that.

Double post

Does the 4870 support DX10.1 and SM4.1 and is better than the 4850?

SM4.1 is only compatible with DX10.1 supported cards. Both cards are (4850/4870). Check individual vendor products to be sure.

The 4870 just runs everything faster. It all depends on budget.

In this case though, there is no ambiguity. All 4850s and 4870s support DX10.1/SM4.1.

The 4870 will run everything about 10% faster than a 4850 because it is the same chip, just running at a 10% higher speed.