Radeon 4650 install causes 100% CPU usage

System: ECS RS482-M motherboard with latest BIOS, 1.5 GB RAM, Athlon 3700+. The motherboard has low-level built-in ATi graphics, but I was running an nVidia 8400 GS graphics card. The machine worked very well under both the Windows 7 beta and then the release candidate.

I wanted to upgrade the graphics a little, so I bought a cheap Radeon 4650 card from Newegg.com. The brand is HIS.

Unfortunately, with the new card installed, the machine runs painfully slowly. (I.e., boot-up takes ~ 5 minutes; it takes forever just to do something simple like open the Device Manager, etc.) The Task Manager indicates that the CPU is pegged at 100%, but none of the running processes account for this. The slowness seems to occur from the instant the Windows 7 start-up process begins. The driver for the new card has been installed, and is supposedly "running normally," but it doesn't make any difference in how the machine is running. I've booted in Safe Mode, with almost the same result (CPU running in the 90+% range continuously for no apparent reason, machine running bog-slow), and I've tried some of the various other options you can get by hitting F8 at startup; nothing helps.

If I remove the new card and put the old nVidia one back in, it reinstalls itself and everything is fine. If I start up with nothing in the PCI-E slot, and the monitor hooked up to the built-in graphics connector, the built-in graphics installs itself and everything is fine. Either way, if I then re-install the Radeon card, the problem returns.

If I remove the hard drive I have Windows 7 installed on, and replace it with my XP64 drive, the 4650 card works fine. (When I first installed it, the 100% CPU thing was happening, but after the driver for the card was installed and the machine rebooted, it was fine.)

I'm stumped. Is there anything else to try, short of re-installing Windows 7?

Are you running the latest Catalyst driver set for the card? Officially v. 9.6

32 Bit - Drivers & Tools | GAME.AMD.COM

64 Bit - Drivers & Tools | GAME.AMD.COM

Make sure to download and install either one depending on what version of Win7 your running, reboot....and see if it corrects the issue!

Another data point: the Resource Monitor is showing me that "System Interrupts" ("Deferred Procedure Calls and Interrupt Service Routines" are what is tying up my CPU (fluctuating in the high-80's/mid-90's range).

Well, disabling the "High Definition Audio Controller" as described here: CPU Usage 100% seems to have stopped the massive system interrupts issue. The computer now feels as if it is back to normal, in terms of response time, program loading, etc. But the Task Manager is still indicating continuous 100% CPU usage. The Resource Monitor is showing Services at around 17-20%; Processes at or near 100%. Very puzzling . . .

DarkXeno said:

It sounds like windows is confused on what driver to use. First have the Nvidia card in and boot into safe mode and removed all drivers and the device from device manager, then shutdown the machine and remove the card, boot into normal mode with just the onboard video card. Reboot into safe mode and again remove all video drivers and the device from device manager. Reboot the machine and enter BIOS, then disable the onboard video card and shut the machine down. Install new ATI card and boot install drivers and see how that does for you. I know its a long process but it will make sure that no other drivers and devices are trying to start and create mulitple screen outputs which could be slowing the machine down.

+1

It's the correct thing to do - disable the onboard video in the BIOS.

After a restart, the CPU readings were back to normal. Disabling the "high definition audio controller" was all that was needed.

It seems this "High Definition Audio Driver" is a common issue to all ATI cards and no matter the OS is Vista or Win7. I have a new 4350 card and is experiencing exactly the same symptom (both in my Vista & Win7 partitions, no matter 32-bit or 64-bit). By disabling the driver, my CPU usage drops immediately.

Now that I'm planning to buy a new HDTV and hook it to my 4350 HDMI port. What'll be the consequence if I disable this driver? Will this inhibit the sound from transmiting to my TV through HDMI?

Please advice. Many thanks.