I will also have a USB keyboard, USB mouse, Iomega 2TB external HDD, Logitech G35 Headset, 2xUSB flash drives and occasionally I will have my phone USB cabel.
This is the case I'll be using, IN WIN Dragon Rider.
With the case I will have 2x120mm, 1x120mm LED and one 220mm LED fan + the H50 120mm fan.
I think that pretty much covers what I'll be using. So my questions are, how big of a PSU will I need and do you think the H50 will fit on an AM3+ motherboard?
I've tried using a PSU wattage calculator tool but I'm no good when it comes to that so I would really love some help in this.
Radeon HD 6870 x1
On your average system the card requires you to have a 500 Watt power supply unit.
Radeon HD 6870 x2
A second card requires you to add another ~150 Watts. You need a 700 Watt power supply unit.
Measured power consumption one 6870 card
System in IDLE = 173W
System Wattage with GPU in FULL Stress = 295W
Difference (GPU load) = 122 W
Add average IDLE wattage ~ 19W (ATI specified)
Subjective obtained GPU power consumption = ~ 141 Watts
Measured power consumption two 6870 cards
System in IDLE = 184W
System Wattage with GPU in FULL Stress = 421W
Difference (GPU load) = 237W
Add average IDLE wattage x2 ~ 19W (ATI specified)
Subjective obtained GPU power consumption = ~ 275 Watts
IN SHORT: 700w would be plenty for Crossfire 6870's
Look for brands such as; Corsair, XFX, SeaSonic, Enermax, Antec
At minimum look for 80 PLUS BRONZE rated. Silver/Gold is better but also comes at a price.
Modular PSU is recommended for easier cable management.
I'm not sure exactly how much current the gpu's draw, but current wisdom says that for two 6870's in addition to all you're other stuff, an 850W power supply with a good strong 12v rail (or two) should be right on the money. Here's an example of a good PSU for you. http://www.newegg.com/Product/Product.aspx?Item=N82E168...
I include my external HDD, keyboard, mouse, flashdrive and phone charger in the USB list. I'm unsure about my motherboard, if it's Regular or High-End. Also not sure about the "Pump Relay" thing. I didn't find the Corsair H50 in the liquid cooling set so I just added one just in case. Also sett it to 100% load, just in case .
Other than me being a little unsure it seems alright.
Just calc'd your build with "high-end desktop" and got 631w recommended. Even with capacitor ageing, 700w is enough, 750w if you really want to be safe
September 2, 2011 3:24:31 PM
Alright so with "High-End Desktop" I get,
Minimum PSU Wattage: 744 W
Recommended PSU Wattage: 794
Now, just one question, my HDD is at 7200RPMs but it's still a regular SATA and not a high RPM SATA?
Again I included my external HDD, keyboard, mouse and other stuff in the USB Device list. I'm not even sure if my external HDD drains anything from the PSU because it has it's own power cable. Not quite sure about the keyboard and mouse though, they can't require much wattage at all. It also says "Other Hardware: Keyboard & Mouse (included)".
Just calc'd your build with "high-end desktop" and got 631w recommended
What did you do to get such a low one? Can you post the print thingy?
Keyboard and mouse aren't included in USB devices (they are added automatically).
SATA HDD I included as a High-RPM, again just to be safe (theres a good chance High-RPM is classed as 10,000 - but nevermind, slower will use less)
If your external HDD is powered externally this also doesnt need to be included in USB devices.
The reason your getting such high wattage suggestions is because your putting capacitor ageing % on. You only need to apply more than 10% if your PC is going to be constantly running 24/7. Most PSU's are rated for 100,000hours so very little capacitor ageing will occur. Having system useage at 100% will also never ever happen during general use. The only time your going to be running at 100% load right across your build on both GPU's and your CPU is if your running some super intensive benchmarking tools such as prime95.
September 2, 2011 3:37:52 PM
100,000 hours?! That's like 11 years
I just put 100% load to be sure.
But this is great news, I guess I can keep using my Corsair TX850W