In this thread you will find multiple remedies for a common flickering issue among the recent HD series of cards. Although the same general principles apply to some of the GeForce nVidia cards, the information here is specifically targeting the ATi Radeon™ family.
First of all DO NOT and I repeat do not fix the flickering issue via installing Riva Tuner. RT is a fantastic piece of software and I highly recommend it to anyone who is keen on seeing what goes on behind the scene and enjoys taking full control of the hardware side of the system, but it's not the solution for this particular problem... Here are more details:
The flickering is a common occurrence with ALL (...yes all) VGA cards that are overclocked by default by the manufacturer beyond the recommended 900 MHz memory clock. This phenomenon happens regardless of the chosen PCB manufacturer (Asus, Gigabyte, XFX, Powercolor, Sapphire, HIS and so on) when the operating system switches profiles within the graphic card. This is done to adjust performance settings according to the users interaction with the system by consuming less power at off-peak thus prolonging the VGA service life.
As discovered by previous users of this thread, With some ATI ® cards overclocking by the manufacturer has become an issue but underclocking the RAM frequency completely resolves the issue. I fully understand that these cards were marketed with the catch phrase of having that extra performance benefits and that was how consumers were lured into paying the premium over their counterparts but unfortunately this technical glitch has turned the strength into a weakness and the promises performance does not materialize. By using the default ATI Overdrive™ feature you can safely reduce the frequency at to match the off-peak 900 Mhz (at peak game usage or off peak browsing) while still taking advantage of the overclocking provided by the GPU frequency management module. In other terms while you lose 25 MHz of RAM performance via the CCC™ limit, the GPU clock is managed flawlessly and when needed, your core clock speed is increased from its default value to the recommended overclock value. This constant adjustment does NOT happen with Riva Tuner and that is why there are no screen flickers happening. When you overclock with Riva tuner (which ever version it may be) to the recommended default factory setting (ie: 780 or 800 @ 925 or 950 MHz) the graphic card is constantly idling at that peak frequency (unfortunately in the pre OC-ed VGA it's the maximum that the card can safely handle). If you monitor the behavior of the VGA with Riva Tuner it's evident that it does not change the values to the desirable idle values (500 @ 900 Mhz) once the gaming application has terminated or you are working with 2D applications. This constant exposure to the highest overclocked voltage along with the inevitable heat sink mishaps and environmental temperature variations will soon lead the way to the famous VPU recovery scenario which plagues many HD4800 series cards, rendering the VGA useless and dramatically degrading your gaming experience with constant disruptions, system failure (hangs) and the blue screen of death. The VPU itself is not the problem, but it's an indication that the system is vulnerable at certain operating scenarios.
Here is the temporary solution for the average know-how user until there is a permanent fix for the RAM issue:
- Undo whatever (damaging) procedure you have done so far
- CLEAN Install the latest drivers (FROM ATI®)
- Enable ATI Overdrive™ (bypass the confirmation prompt)
- Underclock your "Memory Clock" to 900 MHz
- Apply changes
In most cases the fan control does NOT need adjustments [if the PCB vendor has done the profiling correctly]. You CAN install Riva Tuner after this, as it's a very nice addition for the enthusiast BUT do not overclock the VGA with it (or any other software).
Clearly you must repeat this for every new system that you install this class of VGA on - obviously the repetition includes OS changes and driver updates as well. If you are an advanced user, you can easily eliminate the undesirable flickering permanently from the graphics card hardware itself (independent of OS and OC Software) by flashing the EPROM. Modifying the Bios is something that I will not go into details here because the procedure has a high risk factor for the ordinary user and if an individual qualifies as an advance user he/she already knows the details.
I tried to explain the process as best as I can, I hope it helps all you gamers out there. Just in case you need further assistance I will check back on this thread later on, unfortunately I prefer not to disclose any personal contact detail here at this moment.
Best of luck
First of all DO NOT and I repeat do not fix the flickering issue via installing Riva Tuner. RT is a fantastic piece of software and I highly recommend it to anyone who is keen on seeing what goes on behind the scene and enjoys taking full control of the hardware side of the system, but it's not the solution for this particular problem... Here are more details:
The flickering is a common occurrence with ALL (...yes all) VGA cards that are overclocked by default by the manufacturer beyond the recommended 900 MHz memory clock. This phenomenon happens regardless of the chosen PCB manufacturer (Asus, Gigabyte, XFX, Powercolor, Sapphire, HIS and so on) when the operating system switches profiles within the graphic card. This is done to adjust performance settings according to the users interaction with the system by consuming less power at off-peak thus prolonging the VGA service life.
As discovered by previous users of this thread, With some ATI ® cards overclocking by the manufacturer has become an issue but underclocking the RAM frequency completely resolves the issue. I fully understand that these cards were marketed with the catch phrase of having that extra performance benefits and that was how consumers were lured into paying the premium over their counterparts but unfortunately this technical glitch has turned the strength into a weakness and the promises performance does not materialize. By using the default ATI Overdrive™ feature you can safely reduce the frequency at to match the off-peak 900 Mhz (at peak game usage or off peak browsing) while still taking advantage of the overclocking provided by the GPU frequency management module. In other terms while you lose 25 MHz of RAM performance via the CCC™ limit, the GPU clock is managed flawlessly and when needed, your core clock speed is increased from its default value to the recommended overclock value. This constant adjustment does NOT happen with Riva Tuner and that is why there are no screen flickers happening. When you overclock with Riva tuner (which ever version it may be) to the recommended default factory setting (ie: 780 or 800 @ 925 or 950 MHz) the graphic card is constantly idling at that peak frequency (unfortunately in the pre OC-ed VGA it's the maximum that the card can safely handle). If you monitor the behavior of the VGA with Riva Tuner it's evident that it does not change the values to the desirable idle values (500 @ 900 Mhz) once the gaming application has terminated or you are working with 2D applications. This constant exposure to the highest overclocked voltage along with the inevitable heat sink mishaps and environmental temperature variations will soon lead the way to the famous VPU recovery scenario which plagues many HD4800 series cards, rendering the VGA useless and dramatically degrading your gaming experience with constant disruptions, system failure (hangs) and the blue screen of death. The VPU itself is not the problem, but it's an indication that the system is vulnerable at certain operating scenarios.
Here is the temporary solution for the average know-how user until there is a permanent fix for the RAM issue:
- Undo whatever (damaging) procedure you have done so far
- CLEAN Install the latest drivers (FROM ATI®)
- Enable ATI Overdrive™ (bypass the confirmation prompt)
- Underclock your "Memory Clock" to 900 MHz
- Apply changes
In most cases the fan control does NOT need adjustments [if the PCB vendor has done the profiling correctly]. You CAN install Riva Tuner after this, as it's a very nice addition for the enthusiast BUT do not overclock the VGA with it (or any other software).
Clearly you must repeat this for every new system that you install this class of VGA on - obviously the repetition includes OS changes and driver updates as well. If you are an advanced user, you can easily eliminate the undesirable flickering permanently from the graphics card hardware itself (independent of OS and OC Software) by flashing the EPROM. Modifying the Bios is something that I will not go into details here because the procedure has a high risk factor for the ordinary user and if an individual qualifies as an advance user he/she already knows the details.
I tried to explain the process as best as I can, I hope it helps all you gamers out there. Just in case you need further assistance I will check back on this thread later on, unfortunately I prefer not to disclose any personal contact detail here at this moment.
Best of luck