I think I just built the best budget build ever haha.
CPU: AMD Sempron 140 - Fleabay, £15
Motherboard: MSI 785GM-E51 - Ebuyer, £50
RAM: 4GB OCZ 1333MHZ CL7 1.65V - Fleabay, £40
PSU: CoolerMaster Silent Pro M 500W - Fleabay, £25
That totals £130. Obviously the things are worth more than though. Case and HDD is just my spare bits. Motherboard is pretty nice in how it has integrated HD4200 which seems to play all HD video with no problems. I didn't test out any games though.
Unlocked the CPU to a dual core "AMD Athlon II X2 440/ AMD Athlon II X2 4400e" not sure which exactly is the right one on CPU-Z. As a single core it was running at 30 degrees idle.
Can't do any testing to the unlocked CPU at all as I can't see the temperature with CPUID, speedfan, everest, CoreTemp or RealTemp. I've searched around on google and it seems other people have the same problem. 3D Mark Vantage also said system was unidentified or something and got stuck on "Scanning system specs" so I can't benchmark it with that either.
The unlocked dual core sure owns though, I haven't tried a core voltage of more than 1.45V but the chip doesn't seem to want to boot with any combination of 4Ghz. I've not overclocked an AMD system before so I've just been messing about with the system really. I set the Core Voltage to 1.48V in BIOS (1.45V-ish in CPU-Z and surprisingly under load it was also roughly 1.45V, no Vdroop oddly enough), set the NB Voltage to 1.2V and HT voltage was linked to it and it was 1.26V or something. SB Voltage I upped to 1.3V
The system seems stable at 3.8ghz however after a few rounds of Prime it errors out or restarts.
I backed it down to 3.6ghz and Prime seems stable enough but I didn't do it over long periods. I dunno what the temps are though as I can't test it. Perhaps the reading in CPUID is right which is a bit hot as max temp for these are meant to be 65 degrees.
No matter what the speed is, SuperPi seems really slow though. I recall having around 15s for my E5300 at 3.6ghz which also has 2MB L2 cache too. Weird. Guess architect really matters.
This is all done with the stock cooler by the way. (The one WITHOUT the copper heatpipes) I did get Noctua to send me an AM2/AM3 bracket but by the time it arrives I properly won't be bothered to test the system out again haha.
So yeah, in the end £15 for a 3.6ghz dual core processor seems pretty good
EDIT: I've thought of a "semi"-benchmark that should work, Windows Experience Index. Gonna run it in a moment.
Processor: 6.9
Memory (RAM): 5.9
Graphics: 4.2
Gaming Graphics: 5.5
Primary Hard Disk: 5.4
Not sure why the memory is so bad, 1424mhz CL7 shouldn't be that bad.
My system on the left: <-
Processor:6.9
Memory (RAM): 6.9
Graphics: 7.3
Gaming Graphics: 7.3
Primary Hard Disk: 5.9