Urgh! PC upgrading confusion.....please help!

roundthebend · October 2013

Our current PC is a bit old and my son wants to play some games on it. So, he's going to buy a graphics card to stick in it. We've worked that this XFX AMD Radeon HD 7750 2GB will fit and give a nice little boost, in theory.

We're just about to buy and then realise that it needs a 450W PSU, but ours is only 255W.

So, can we just buy a cheapy 520W and it'll be a straight swap or do we need to make sure the connectors are all compatible with the current components?

mudslide73 · October 2013

It depends on how old the machine is. The standard connectors for motherboards and hdd/dvd drives haven't changed for a few years so you should be ok. Just make sure you have enough connectors for your drives.

roundthebend · October 2013

Ta

Myranda · October 2013

How old is the PC?

Has it been running with a 255W PSU for a while? If so I can't imagine a 7750 needing 200W (it's I think a 65W part)

PSUs are a standard though (for the most part... but it should be advertised as different if it is).

Also. What games does he want to play? The 7750 isn't exactly a powerhouse.

Tell us more and we can shine more lights on things

roundthebend · October 2013

The PC is about 5 years old, running a Core 2 Duo E6300 at 1.8MHz I think. 4GB RAM.

He plays Minecraft and WoW just now and wants to record video of his gaming. He says it's working quite well today with WoW and video recording, so the GPU might give it some extra.

We're planning to upgrade the CPU and maybe put an SSD in. It's a gradual process as we haven't got budget for it.

digitalscream · October 2013

Hang on...what is the PC? If it's a Dell, for example, I know they used to use custom power supplies (same connector, different pinout).

Also, for video editing - check out the capabilities of the software you're using. I use Sony Vegas, and it doesn't work very well with OpenCL cards at all...it vastly prefers CUDA (which is NVidia-only).

roundthebend · October 2013

It's a Zoostorm. The PSU is a cheap but of generic crap I think but it sounds like it'll do. He's using something called Fraps to record the video and audio I think.

digitalscream · October 2013

Then yeah, it should be standard ATX. I would really advise getting a new PSU to go with it - no need to go nuts with the crazy-expensive enthusiast modular stuff, just spend £25 on a decent 550W unit.

Remember - that 255W PSU of yours (which is unlikely to be a high-quality PFC part) is probably only capable of about 160W before voltages start to drop, PSU temperature starts to rise and the computer gets unstable. The consequences of a blown power supply can be really expensive - I've seen the regulator caps on motherboards literally exploded (taking the CPU and memory with them) and hard drives irretrievably wrecked (well, irretrievable without serious expense). Bear in mind that PSU warranties specifically exclude damage to other components, and with good reason. For the sake of an extra £25 or so, it's not worth the risk...especially when you're talking about adding in a relatively powerful card.

A few numbers for you...

The HD 7750 uses a max of 50W at full chat (assuming that its fan isn't obstructed)

The E6300 has a TDP of 65W

Mainstream motherboards from that generation use about 35W

3.5" 7200rpm hard drives use an average of about 7W

RAM from that generation uses about 2W

A SATA DVD drive uses about 30W

The total of all that is 189W. Or, to put it another way, 159W until you use the DVD drive, at which point your PSU is pretty likely to go into a tailspin and things are going to start going wrong.

crunchman · October 2013

If you are talking about a graphics card, and a new PS now, followed by a new processor and SSD a bit down the line you are talking a fair bit of the price of a new machine.

Also, there will be a limit to what you can do with a 5 year old motherboard. You won't be able to put all the latest parts in it.

Myranda · October 2013

I like crazy expensive modular stuff.

Especially as there are a good number that are 80+ platinum rated. (which is missleading as the 80+ standard was for 80% efficiency... but the Platinum is 90% efficient - also... Bronze, Silver, Gold, Platinum then Titanium ... since when did going up in rarity of metals like medals end in titanium?!).

But... yes. They are often stupidly expensive. The one I want is £125 and that's cheap for the efficiency and mudular pluggyness

roundthebend · October 2013

crunchman said:

If you are talking about a graphics card, and a new PS now, followed by a new processor and SSD a bit down the line you are talking a fair bit of the price of a new machine.

Also, there will be a limit to what you can do with a 5 year old motherboard. You won't be able to put all the latest parts in it.

Agreed, but with the gradual upgrade path my son gets to enjoy better gaming now and learns about how to put bits together. It also spreads the cost, because if we tried to save the chances are he'd get bored of it and want to spend on something else.

imalone · November 2013

What @digitalscream said, especially if it's the stock PSU and the computer is as it came. The manufacturers will often fit with a PSU that can handle what's in the box and no more. Going 550/600W means not having to worry about it, I've several times had problems with underpowered or failing PSU. It's often something people cut corners with because you discover it needs upgraded as a result of doing something else and it's not very exciting. Check number of connectors for drives, it's not a standard, but you're less likely to have problems if the computer hasn't been upgraded before and there's not a lot of extra stuff in it already.

roundthebend · November 2013

Ok, so with a view to future upgrades it sounds like a much meatier PSU is a good idea. Should I be brand aware or just get something from a reputable dealer that fits the spec? £25 is Ok. I'll buy the PSU since he's buying the GPU.

WYNIR0 · November 2013

The P C forums are full of advice that you should go for a name brand. I've never had problems myself but it is sensible advice. If going for a name I'd generally look at Corsair, Antec, or Coolermaster. You may have trouble getting a 550/600W name brand supply for less than about £50 though.

digitalscream · November 2013

OK, so prices have gone up a bit since I last looked...

http://www.aria.co.uk/Products/Components/Power+Supplies/Non-Modular+650W+or+less/OCZ+OCZ-CXS500W-UK+CoreXStream+Series+500W+Power+Supply+?productId=57131

http://www.scan.co.uk/products/450w-zalman-psu-zm450-gs-quiet-fan-atx-v23

http://www.scan.co.uk/products/550w-ezcool-silent-quiet-fan-atx-psu

I know the last one isn't one of the big brands, but I've found their PSUs to be pretty good in the past when building machines to a budget.

WYNIR0 · November 2013

http://www.ebuyer.com/253900-coolermaster-elite-power-500w-psu-rs500-psapj3-it

digitalscream · November 2013

WYNIR0 said:

http://www.ebuyer.com/253900-coolermaster-elite-power-500w-psu-rs500-psapj3-it

Good call.

roundthebend · November 2013

Thanks guys. Will these non-modular PSUs give me some future proofing should I want to add a more beastly CPU and perhaps an SSD later?

digitalscream · November 2013

roundthebend said:

Thanks guys. Will these non-modular PSUs give me some future proofing should I want to add a more beastly CPU and perhaps an SSD later?

SSDs use a lot less power than standard hard drives - typically 0.8W to 2.5W, compared with 6.5W to 9W for standard desktop hard drives.

For what it's worth, I have a Coolermaster 550W PSU in my main machine, running a Core i7 2.66GHz (130W TDP), SSD, 7200rpm 3.5" drive and a GeForce GTX 460. Absolutely no problems with voltage drop at all.