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R9 270 on a 430W PSU?

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Would the above work okay? The machine currently has an old x1800xt which also requires 1x 6 pin PCI-E connector and that is still running flawlessly since the card came out!

The plan is to buy the card now (MSI Radeon R9 270 Gaming 2G AMD Graphics Card - 2GB), then in a couple of months replace the board, CPU and RAM to a mid range AMD setup, maybe a 6 core and 8GB of memory.

Is this plausible with keeping everything else as it is?

Many Thanks.
 
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What PSU do you have?

You'll need something that is rated for at least 25A on the 12V rail, 30A would be a lot better.

You can work it out based on the Thermal Design Power (TDP) devided by the 12V it is supplied with to get the amount of amps required to provide the power you have. I always add at least 100W for the CPU and then a few extra Amps for Hard Drives and fans in the case just to be safe. The equation is Power (Watts) = Voltage (V) x Current (I, Amps).
 
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Should have mentioned the make, sorry about that!

It's a Seasonic, was expensive back in the day but never had a single problem with it. I've got a photograph of the sticker somewhere so will have a look.

Thanks for the replies.
 
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I've been using a molex to 6 Pin since the machine was built. Always been rock solid so figured it should still be okay to use. From what I can see the x1800xt is a power hungry card, or at least was when it was released.

The rest of the system is basic, 1x HDD, 1x SSD, optical drive and a couple of case fans.
 
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I believe the x1800xt uses about 100w while the 270 will be closer to 150w.

It will probably still work fine but I have a thing against using adapters :) For 40 pounds I'd definitely recommend upgrading the psu just to be safe. Also, it has 2 x 12v rails but you don't know how they're split. The one you're using to power the gpu might also be powering the cpu, if that's the case there will be some trouble as both rails are under 180w each.
 
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That PSU will be fine, even accounting for capacitor ageing you still have power spare with it. The PSU takes care of splitting the rails dynamically so if more power is needed and one rail is at full load the power requested will be delivered via the spare rail. There is no need to spend money on another PSU when your current one is fine.
 
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That PSU will be fine, even accounting for capacitor ageing you still have power spare with it. The PSU takes care of splitting the rails dynamically so if more power is needed and one rail is at full load the power requested will be delivered via the spare rail. There is no need to spend money on another PSU when your current one is fine.

Where did you get this info?

The only difference between a single and multi rail psu is the 'rail' limitations so this makes no sense. Pretty sure each one is given its limit (as per the spec), if its exceeded the psu's OCP will kick in and shut it off. Example of a psu which lists how the rails are split

http://images.anandtech.com/doci/5758/leist.PNG
 
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Where did you get this info?

The only difference between a single and multi rail psu is the 'rail' limitations so this makes no sense. Pretty sure each one is given its limit (as per the spec), if its exceeded the psu's OCP will kick in and shut it off. Example of a psu which lists how the rails are split

http://images.anandtech.com/doci/5758/leist.PNG

The power being delivered by the PSU will be higher than the rating for the individual rails because the PSU only produces one source of 12V for the computer, it just delivers that 12V over multiple rails because it is safer to do so. Multiple rails carrying less current each are cooler than a single rail carrying the full current so there is less risk of burning out the rail at high loads.

The power law equation is my guide for how much power the PSU can deliver (P = I * V, P = Watts, I = Amps, V = Volts). The one you posted is rated at 492W on the 12V rails and as such it can only deliver that power when using a current of 41A.

If you'd like to read more about Single vs Multiple rail PSU check these posts out:
http://www.jonnyguru.com/forums/showthread.php?t=3990
http://www.overclock.net/t/761202/single-rail-vs-multi-rail-explained

I couldn't find the review I read that took apart a PSU and showed where the 12V rail is and how it is split. It doesn't act as two separate rails giving power to different parts of the computer, it is one rail that is converted into 2 to transfer power from one side of the PSU to the other safely; there is only one origin point and the rails come together at one end point; they act as a parallel circuit splitting the current between them.
 
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The power being delivered by the PSU will be higher than the rating for the individual rails because the PSU only produces one source of 12V for the computer, it just delivers that 12V over multiple rails because it is safer to do so. Multiple rails carrying less current each are cooler than a single rail carrying the full current so there is less risk of burning out the rail at high loads.

The power law equation is my guide for how much power the PSU can deliver (P = I * V, P = Watts, I = Amps, V = Volts). The one you posted is rated at 492W on the 12V rails and as such it can only deliver that power when using a current of 41A.

If you'd like to read more about Single vs Multiple rail PSU check these posts out:
http://www.jonnyguru.com/forums/showthread.php?t=3990
http://www.overclock.net/t/761202/single-rail-vs-multi-rail-explained

I couldn't find the review I read that took apart a PSU and showed where the 12V rail is and how it is split. It doesn't act as two separate rails giving power to different parts of the computer, it is one rail that is converted into 2 to transfer power from one side of the PSU to the other safely; there is only one origin point and the rails come together at one end point; they act as a parallel circuit splitting the current between them.

This doesn't really explain anything to be honest. In fact both links you posted imply the load is not distributed among the rails, instead each powers a certain component like in the screenshot I posted above.

An FSP Epsilon 700W has ample power for any SLI rig out there, right? But the unit only comes with two PCIe connectors. The two PCIe connectors on the unit are each on their own +12V rail. Each of these rails provides up to 18A which is almost three times more than what a 6-pin PCIe power connector is designed to deliver! What if I want to run a pair of GTX cards? It would have been ideal if they could put two PCIe connectors on each of those rails instead of just one, but instead those with GTX SLI are forced to use Molex to PCIe adapters. Here comes the problem: When you use the Molex to PCIe adapters, you have now added the load from graphics cards onto the rail that's also supplying power to all of your hard drives, optical drives, fans, CCFL's, water pump.. you name it. Suddenly, during a game, the PC shuts down completely.

So multi-rail is inherently safer, correct? Yes, but early on there were some problems. You see, when multi-rail units were first introduced, the specification at the time was poorly written, and power supply engineers made a mistake; they put all the cables that power heavy-draw components like your CPU, mobo, and graphics card(s) on one rail, and all the light-draw stuff like HDDs and fans on the other. This meant that you had one rail that might be pulling, say, 24A, and another pulling 5A.
 
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This doesn't really explain anything to be honest. In fact both links you posted imply the load is not distributed among the rails, instead each powers a certain component like in the screenshot I posted above.

It seems you are right. I can only find the bequiet! Dark Power Pro power supplies with a switch that changes the system from 4 rails to single. I must have assumed from this functionality that it was common to have the rails done in parallel.

I can't find any reference to rails powering separate bits for Enermax PSUs that I use either which would have confirmed my assumption when I initially made it.

Quick update. Will be able to get hold of a barely used 500W, namely this one:

http://www.silentpcreview.com/article241-page2.html

The review suggests one 12V is used exclusively for the CPU and the other for the rest of the system. Even if it is the case of it being split, there should still be plenty of breathing room to run the R9 270 and an FX 8320 (overclocked) from the looks of it.

Your current PSU will be fine. If you would rather be safe then sorry then I wouldn't get another old PSU, you'd be better off getting a new one.

SuperFlower Golden Green HX 450W - £54

or

Seasonic G Series 450W - £65

The above options would be my short list for a power supply to run your system. Both are gold rated, 5 year warranties and are manufactured in house rather than using an outside manufacturers design.
 
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Everything I need to replace keeps bumping the price up more and more.
I fully agree that a high quality PSU is essential. The 500W I linked to above has been used far less than my own and well taken care of. Seems a better idea to go with that one.

Thanks for the reply.
 
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