To overclock the ATI Radeon HD 5830 1GB graphics card, we used the ATI Overdrive utility that is part of the CATALYST Control Center. When you ‘unlock’ the ATI Overdrive, you can manually set the clock and memory settings or let the ‘auto-tune’ utility set the frequencies for you.
The bad thing about using ATI Overdrive for overclocking is that it only goes up to 775MHz on core clock and 1125MHz on the memory frequency! The Sapphire Radeon HD 5850 Toxic video card that we are trying to overclock is already 765MHz on the GPU core clock and 1125MHz on the memory clock, so there really isn’t much play using this utility. A 10MHz boost in the clock speed could be reached, but what fun is that?
In order to really push the Sapphire Radeon HD 5850 Toxic 1GB graphics card like it should be, we had to use a combination of two free software programs. They are the AMD GPU Clock tool and MSI AfterBurner. By using these two utilities you will be able to set the clock speeds (AMD
GPU Clock Tool) and then you can manually set the fan speeds (MSI AfterBurner). If you try to manually set the fan speed in CCC and then use these programs to change the clock frequencies with the AMD GPU Clock Tool, you will find that when you launch a 3D application the fan defaults to auto speeds. This is where you need the MSI AfterBurner application as you can manually set the fan speed to the percentage you want and it won’t go back to default fan speeds. In order to get the best overclock possible you really need to use the AMD GPU Clock Tool and MSI AfterBurner as you can adjust the clock frequencies and fan speeds properly.
The Sapphire Radeon HD 5850 Toxic comes pre-overclocked to 765MHz on the Cypress
core and 1125MHz on the GDDR5 memory (4500MHz effective). This is a nice boost over the ATI reference design of 725/1000MHz! We were able to read 901MHz on the GPU clock at 1200MHz on the memory clock. This is a 24% increase on the core clock and a 20% increase on the memory clock from a reference design Radeon HD 5850! Very impressive! The card was rock solid at 901MHz on the core and had more room in it, but we called it good enough since we aren’t going after any air cooled Radeon HD 5850 records!
The Sapphire Radeon HD 5850 Toxic 1GB Video Card Stock: 765MHz/1125MHz:
The Sapphire Radeon HD 5850 Toxic 1GB
Video Card Overclocked: 900MHz/1200MHz:
Running 3DMark Vantage with the Extreme preset we got a score of X7855 with the card at Sapphire Toxic retail boxed settings. The score went up to X9052 3DMarks when manually overclocked beyond the factory overclock. This is an insane improvement and an increase of over 15%!
This overclock was also rock solid and the card had more left in it for those that have more time to finely tune the card to the optimal settings for performance. With the performance on this card nearing that of a stock Radeon HD 5870 we are very impressed. Notice 3DMark Vantage shows our overclocked card is ~25% faster than the reference card, which is within the margin of error as the core clock is ~24% higher!