Voltmod help for a 4890 by flashing a BIOS

[Janet J]

Hello, I have some time trying to overclock my graphics and unable to move from 910 MHz on the core I've thrown to make a change in the parameters of the graphics card BIOS to achieve a higher ceiling when climbing the frequency of the graphics chip. And I will take to pay you a mini-guide if anyone is encouraged to follow my steps, let us begin :

The first step is to determine the conditions of our graphics card, and I mean not only to know the manufacturer and "part number", but to find out if we use the reference PCB. Having the reference PCB may not be very important, but do not have it run the risk of having an error when flashing our graphics card, so we'll have to click a chart in another PCI-E that we free to reflash the BIOS original.

In my case part of this chart:

As we can see, the PCB design is quite different from the reference used by ATI, so I will not be able to use the BIOS from another manufacturer to replace it, I'll have to edit the parameters contained in my own BIOS. On the other hand, is a good thing, the VRMs are cooled by a fairly large heatsink and the heatsink of the chip is quite generous (Zalman VF1050), allowing us to put the screws a little more. They also say that this plot comes to 900/975 instead of 850/975 to which we have used the benchmarks.

[Janet J]

To this end we need two programs, one for our BIOS file (and re-flash) and another to modify the values it contains. To read and record the BIOS Winflash we will use the values and modify the Radeon Bios Editor (RBE from now).

First, open the RBE and integrate the Winflash within it to give us things to do click on the button "Acquire Flash", then click on "Browse" and locate the executable Winflash.

To read our BIOS must first one to click where it says "Analyze" to find our graphics card. To load data from the BIOS in the RBE click "Acquire BIOS", it will automatically fill in all fields with data from the BIOS.

VERY IMPORTANT: Here we make a backup of the original BIOS and keep it in case things go wrong during flashing. This give the "Save" and save the file. I strongly recommend doing this.

Now let's change the BIOS settings so that our graphics faster, in itself only going to touch the voltage of the chip, to increase the frequencies of the chart was using the ATI Overdrive will do, much easier. We can also change values of the fan chart, because for example my fan when the VGA is 80 º C, is only 50% and I do not like too see chart so hot and now, is going to warm up a bit more.

[Janet J]

To change voltage settings click on "Clock Settings" to change the page and click where it says "GPU Registers."

Now we have to choose the voltage for use when the GPU is under load (working), the other profiles are not going to play). Presumably the reference voltage fed to an RV790 is 1.313 V, in my case, being an overclocked version number comes to 1.35 V. To know that tensions can consider to be safe I downloaded a BIOS from a Sapphire Toxic HD 4890 and an Atomic and load voltage is 1.4 V specified and ASUS EAH4890 eg Voltage Tweak allows you to upload up to 1, 45V and 1.4 which I interpret that section V should be a safe enough for me, because the left will sink to dissipate the heat and the PCB has the specifications "Ultra Durable" Gigabyte, so it is designed to go well hot. To set the voltage as you type in "0x18" and accept.

We keep the BIOS with a name different from our original BIOS and flash again. Once the process will ask if you want to restart the computer (Yes), and reboot.

To find the tickle our "new" graphic, use the ATITool to scan artifacts and ATI Overdrive to go adjust the frequencies. We strongly discourage the Furmark, excessive force to the supply circuit of the VGA and we'll never reach that level of fatigue in games, so it is silly to force both graphic.

The amendment to 1.4 V I have gone from 910 MHz to 975 MHz without arctifacts in ATITool. A tip, obsessing to reach 1 GHz in clock is not worthwhile if you have to go too high voltage, eg V 1.425 imagine that it would still be safe, but I have to investigate further. We also need to monitor the temperature of the VRM's not shoot too much with us GPUz, give more power to get some more heat. Anyway do not rule out trying to lower it to 1.375 V, somewhat more conservative than the 1.4 V.

Well, I hope it will help you because I think that can also serve other models 5xxx series ATI.

And as always, I am not responsible for any malfunctions caused by improper use / interpretation of this instruction. Beware of graphs, which are more sensitive than micros and motherboards, to gird tensions that are specified by the major manufacturers, if the place is because they are safe. Also eye to temperatures between 80-90º C for the GPU and VRM's can be considered "normal" beyond that is not recommended.