DIGIT-ARC read-only archive · snapshot: July 23, 2026

Implications of Running HD 6870 on CX400

15 posts · originally from https://geek.digit.in/community/threads/implications-of-running-hd-6870-on-cx400.141249/

nbaztec
nbaztec Original post #1
May 24, 2011 at 11:06 PM
The title says all. Plus since CX400 lacks a PCI-E connector, I'd require a Molex-to-PCIe connector.

Suggestions welcome.
skeletor
May 25, 2011 at 3:59 AM
You would be pretty much on the edge.
topgear
topgear #3
May 25, 2011 at 4:02 AM
You'd require 2x Molex-to-PCIe connector and you'll get them with the gfx card for sure ;-)

BTW, what gfx card you're getting I mean brand name ??
Extreme Gamer
May 25, 2011 at 9:55 AM
does the 12v rail have enough amperage?
topgear
topgear #5
May 26, 2011 at 7:06 AM
CX400 should handle his rig if he don't OC his cpu and gpu.
desiibond
May 26, 2011 at 8:47 AM
No. No. and No.

HD6870 takes around 220W on load and 1055T has a TDP of 125W. So, if the system goes on full load, there will be just around 50-75W for other components, which would be too less and could kill the PSU on long run (even if it is Corsair). So, get 500W PSU atleast.
Skud
Skud #7
May 26, 2011 at 10:28 AM
^^Or get a 6850.
MegaMind
May 26, 2011 at 2:18 PM
CX400 comes wit 1 PCI-E connector..
topgear
topgear #9
May 27, 2011 at 3:33 AM
No. No. and No.

HD6870 takes around 220W on load and 1055T has a TDP of 125W. So, if the system goes on full load, there will be just around 50-75W for other components, which would be too less and could kill the PSU on long run (even if it is Corsair). So, get 500W PSU atleast.

HD6870 can consume around ~ 138 Watts under load
Gigabyte Radeon HD 6870 review

AMD Phenom II X6 1055T has a 95W TDP version :
HEXUS.net - Review :: AMD Phenom II X6 1055T 95W CPU review : Page - 1/7

Now read this ( from guru3d ) :

Power consumption

Our test system is based on a power hungry Core i7 965 / X58 based. This setup is overclocked to 3.75 GHz. Next to that we have energy saving functions disabled for this motherboard and processor (to ensure consistent benchmark results). On average we are using roughly 50 to 100 Watts more than a standard PC due to higher CPU clock settings, water-cooling, additional cold cathode lights etc.

Keep that in mind. Our normal system power consumption is higher than your average system.

Measured power consumption - 6870
Advertised TDP = 127W
System in IDLE = 172W
System Wattage with GPU in FULL Stress = 291W
Difference (GPU load) = 119 W
Add average IDLE wattage ~ 19W
Subjective obtained GPU power consumption = ~ 138 Watts

Bear in mind that the system Wattage is measured from the wall socket and is for the entire PC. Below, a chart of measured Wattages per card. Overall this is much higher than reference, this is due to an increased GPU voltage to allow easy overclocking and the standard higher clock frequencies.

Here's andtech guys test system specs ( core i7 920 Oced at 3.33 Ghz ) :
AnandTech - AMD’s Radeon HD 6870 & 6850: Renewing Competition in the Mid-Range Market

and the power consumption result while running a game :
*images.anandtech.com/graphs/graph3987/33245.png

image coutesy of anadtech.com

Source : AnandTech - AMD’s Radeon HD 6870 & 6850: Renewing Competition in the Mid-Range Market

So Cx400W should handle OP's rig safely if he don't OC his CPU or GPU ;-)
Skud
Skud #10
May 27, 2011 at 9:05 AM
Nicely summed up TG.
desiibond
desiibond #11
May 27, 2011 at 9:07 AM
HD6870 can consume around ~ 138 Watts under load


Now read this ( from guru3d ) :



Here's andtech guys test system specs ( core i7 920 Oced at 3.33 Ghz ) :


and the power consumption result while running a game :

image coutesy of anadtech.com

Source : AnandTech - AMD’s Radeon HD 6870 & 6850: Renewing Competition in the Mid-Range Market

So Cx400W should handle OP's rig safely if he don't OC his CPU or GPU ;-)

ah. Looks good. Thanks for correcting me.
mitraark
mitraark #12
May 27, 2011 at 10:13 AM
What is the TDP of i5 760 [ No Overclocking , Never.]? Can i upgrade to a 6870 [ or even a 6850 ] with the CX400 ?
Skud
Skud #13
May 27, 2011 at 10:19 AM
Your CPU's max TDP is 95W, max turbo frequency is 3.33 GHz, the frequency at which Anandtech's i7 920 is running, which in turn is a 130W chip. So based on the information given by topgear, you can safely put a 6870 provided you don't OC.
thetechfreak
May 27, 2011 at 10:20 AM
mitraak said:
Can i upgrade to a 6870 [ or even a 6850 ] with the CX400 ?
You can but its gonna be borderline.

Better get Corsair VX450
topgear
topgear #15
May 28, 2011 at 3:33 AM
@ Skud and desibond - thanks guys ;-)

@ Skud and thetechfreak - core i5 760 @ stock load power consumption is aound 40-50W less than a core i7 9xx cpu at 3.33 Ghz.

@ mitraark - if you don't OC ( cpu and GPU ) cx400 should handle a i5 760+HD6870 just fine.

*images.anandtech.com/graphs/graph4083/35052.png

OMG! i5 760 even less power than a i5 750 !!!

*images.anandtech.com/graphs/sandybridgepreview_082710002107/24416.png

pics courtesy of anandtech.com

Source 1

Source 2

SNow if we take the guru3d's rig and power consumption as example mitraark rig should consume around ~275-280W and CX400 can deliver 336W on it's +12V rail which is just fine ;-)