AsRock Support > AlivenF6G-DVI Motherboard > Main Support page,http://www.asrock.com/MB/overview.asp?Model=ALiveNF6G-DVI
In the list on the left hand side, click on CPU Support Listhttp://www.asrock.com/mb/overview.asp?cat=CPU&Model=ALiveNF6G-DVI
The AMD Athlon 64 X2 5800+ CPU, (Processor), is part number ADA5800IAA5DO.
Operates Up To a maximum frequency rate ('Speed'), of 3.0GigaHertz, has two L2 cache's of 512MegaByte, and uses the Socket AM2 CPU socket.http://en.wikipedia.org/wiki/List_of_AMD_Athlon_64_microprocessors#.22Brisbane.22_.28energy-efficient_65W.2C_G1_.26_G2.2C_65_nm.29
In the CPU Support :List it is not shown.
This is ONLY because the Athlon 64 X2 5800+, came out way after the CPU Support List was compiled. NOT because it isn't supported.
No, I have to amend that,http://forums.amd.com/forum/messageview.cfm?catid=14&threadid=108319
It's because AMD's lack of information, apparently, that AsRock didn't list it.
I don't see the voltage range listed anywhere. (To include AMD)http://www.cpu-world.com/CPUs/K8/AMD-Athlon%20X2%205800+%20-%20ADA5800IAA5DO.htmlhttp://www.newegg.com/Product/Product.aspx?Item=N82E16819103274
At any rate let's go with deductive reasoning, and see if this CPU is supported.
1) You can compare the Athlon 64 X2 5800+, to the other CPU's in the CPU Support List; that are comparable to it, and above it.
Don't even have to go too far.
Look at the ADA6000IAA6CZ, and the ADX6000IAA6CZ CPU's.
The two Athlon 64 X2 6000+ versions.
(Doesn't state that, just the above part numbers)
However I DO notice that the ADX requires BIOS version P2.00, and the ADA only requires BIOS version P1.60
2) The motherboard chipset is an Nvidia GeForce 6100 and Nvidia nForce 430, Or Nvidia GeForce 6150SE and Nvidia nForce 430http://en.wikipedia.org/wiki/GeForce_6_Series#GeForce_6100http://en.wikipedia.org/wiki/Comparison_of_Nvidia_chipsets#For_AMD_processors
May need the P2.00 BIOS update, if not already installed.