Q: I have just completed a self-build PC (my first), using the AMD A8-3870 CPU and Asus F1A75-M motherboard, to which I added the AMD Radeon 6450 graphics card with the intention of achieving CrossFire.
Everything works as it should, except that I am confused about the CrossFire function. With the 6450 installed, there is no monitor output from the motherboard, hence connected to the 6450 I only obtain the 6450’s performance. With the 6450 card removed and monitor connected to the motherboard, the system automatically switches to the CPU’s integrated 6550’s graphics. I checked Asus’s tech forum, which describes changing the default value of the PCI slot to 4x Mode for CrossFire in BIOS> Advanced> Onboard Devices Configuration, but in the BIOS version 0603 that I have, there is no such option. I sent this to Asus support and they asked if the graphics card drivers and BIOS were up to date. I replied that I had downloaded and installed the most recent versions, following which Asus has no come back to me. Can you help please?
A8-3870K APU needs FM1 socket motherboard = ASUS F1A75-M LE FM1 AMD A75
I’m a little confused about your actual issue here, but I’ll try to help as best I can. Your pairing of GPU and APU should support hybrid CrossFire, so there’s no problem there. When you say that you’re getting no output from the motherboard when the 6450 is installed, do you mean in a dual monitor configuration, or you have no monitor output at all? If you’re running dual monitors, then you should connect both to the 6450, as this is the main output card, while the APU is simply working in tandem with the discrete unit to boost performance.
If, however, you have no output at all, then you may have a configuration issue when attempting to use hybrid CrossFire, and Asus tech support may be on the right train of thought. You say you have version 0603 of the BIOS, but the F1A75-M’s latest BIOS version is current 1702. As you’re missing the options suggested by Asus, I’d suggest upgrading the BIOS to ensure you have the latest version with all available options. You can find the latest version at tinyurl.com/7rz3lac.
You also say that you only receive the 6450’s performance when you’re connected to it, but have you run benchmarks to double-check this? In most tests, you should see a noticeable improvement in scores with hybrid CrossFire running. It would be a good idea to run such tests before you make any major system changes, just to double check.