So, 'proper' system builders and online retailers selling prebuilt systems seem to be engaged in a numbers game where they sell one basic gaming PC with a 550W PSU, one higher-spec gaming PC with a 750W PSU, and one super-high-end build with a 1000W PSU. To date of writing, it's still common to see 1000W PSUs paired with a Core i7 and an overclocked GTX 1080. Problem is, a Core i7 and an overclocked GTX 1080 will pull about 340W at most, according to online calculators. As we all know, your PSU should sit between 50% and 80% load for optimal efficiency and temperatures. You don't want it much outside that range. So surely, even with some nice cooling fans, a 280mm closed loop cooler, some HDDs, a modest overclock, a Core i7 and a factory-overclocked GTX 1080, you're still going to be fine on a 550W PSU? Your 80% ceiling is 440W. I can't imagine going over that without the addition of a second graphics card. I'm speccing a build for a customer and have been told to 'spare no expense', but I just can't see a reason to go higher than 550W, even though historically 550W was always the 'small' PSU. Am I wrong?
It's been the case for a long time now (as in, several years) that it's purely a mark of ignorance to buy big PSUs for single-GPU systems. I bought a 775W unit specifically because I regularly bench with two GPUs, but even with a hog like the 780Ti I'm drawing barely 350W at the wall when gaming. Smaller PSUs are optimal for these systems, but hey - how can all the big companies line their purses if everybody buys what is appropriate?! 1000W PSUs are obviously better for "gaming"
I bought my 910w back in 2009. I'd been caught out with weak 12v rails a few years previously (X1950pro needed more juice) so l wanted to make sure it didn't happen again. I figured a single 74A 12v rail should see me right for a while. With hindsight it was perhaps a little overkill.
I've got an EVGA supernova G2 750w, it was like a couple quid more than the 650 at the time I got it. 62A 12v rail, pretty good. I don't need that much, but it'll tide me over for when I finally upgrade.
For my heavily OCed GTX 980 Ti a '750 Watt' PSU came recommended, but since I presume that to mean 'generic 750 junker PSU', I went for a 660 Watt Seasonic Platinum instead According to my UPS it's pulling around 126 Watt, but that's including 3 25" displays at probably ~15 Watt a piece as well. So close to 100 Watt idle, or just under the 20% mark for my PSU. 500 Watt might have been enough for me, I guess, though I did want to have some headroom for OCing and add-on cards as well
There's a reason why system builders are running with greater power capacity than is required. Customers are basically just looking at the numbers and thinking more is better, or it is a sign of the systems performance. Of course that is incorrect, but it is something that is worth keeping in mind. I would leave some growing room in the power supply you choose though. You should leave enough room for another graphics card and maybe a pump if the customer ever decided to watercool. There's no point sticking anally to the power efficiency curve when it won't be noticed on the power bill and it results in buying a power supply that restricts possible future upgrades (and potential future business)
I love mITX, love SFF in general. That is why I really think there is no setup that would need more than 600W PSU. You gonna say - what about multi GPU systems - pointless, get a max single GPU and you are good. Silverstone SFX 600W PSU is an ultimate sweet spot for me. I will never go full form PSU again. No point. PCs should shrink, not to be huge all the time. TJ07 cases and huge PSUs area has passed, let it die, don't keep it artificialy alive...
Sometimes pointless is what PC building is all about or it used to be, same reason people want to overclock or watercool. My old 680 SLI rig on water drew around 600 full load. So that's a minimum 750 watt unit for 80%. Whilst 900 would be required for your 50%. The minimum I'd run a 1080 and 6700k on is a 600 watt psu. To buy a good 600 watt psu is just as expensive as a good 850 watt psu. There's like £30 between the prices of a corsair 650watt RMI ( £86) the 850 watt is £115 so £30 for much more headroom and safety long term. For most users that's a price worth paying for some piece of mind.
This is actually a really interesting point when talking about PSU "size" in terms of power output. The physical size of "performance" PCs has drastically changed as a result of components becoming smaller and technology being more advanced, which is why not all high end graphics cards need to be 12" long. In the same way that physical size has decreased, so has the requirement for power (although it's still possible to get power hungry components... only now the most power hungry CPUs have 15 cores and 30 threads ) Nowadays, many PC users are realising that they have so much empty space inside their cases that there's no reason even to stick with ATX, and the reduction in physical components/total power draw of course has a direct impact on what PSU will be suitable or required. @TheShadow2001, I agree with you on the point of "bigger is better" being some sort of psychological achilles heel, but I would disagree with the idea of buying unnecessarily for future proofing. In many ways, I see the latter as a way to confirm the former without having to be open about it. Get what you need as and when you need it, IMO. It's a brilliant cure for procrastination.
I used to buy lower wattage models but the thing was I would always end up going 2-3 way so it made sense just to buy a larger wattage model and then hold onto it. Back in the day higher wattage models were more desirable than they are now and so went for much more money. These days there's only usually a fiver or a tenner between models so I would still choose the higher wattage model. Having said that though I usually opt for 750-850w, I only ran a 1250w Revolution because I got it for £65 (they're actually a tough sell) and I got the Corsair AX1200 for free. I have absolutely no plans to replace it.
Fair point and I would agree if you were building your own system. But he is building a customer system for someone that wants no expense spared. Throwing an extra 200 watts on a power supply just to accommodate the future whims of a customer is no harm when they want an all out build and are unlikely to complain about the price. If they do, well its easy to cut back the PSU. Its not system future proofing I'm suggesting really, its customer future proofing.
I agree completely. It's actually quite major surgery to replace a PSU especially when for me at least it's usually the first thing to go in so the cables are buried under all of the other cables. For the sake of £20 I would rather my bases be covered.
I think I remember my little SG08 build with an overclocked 4790K and heavily overclocked 980Ti pulling about 340W in games. The Maxwell rig pulls about 1000W when overclocked IIRC and the Pascals pull about 610W. So yeah, when I get folks worrying if a 1000W PSU is good enough to power their brand new 1080, I do . However, there's an unspoken rule that PSUs operate at their best when at ~50% load. This lines up quite well with Nvidia's recommended PSU wattages. One other thing that irks me is that people forget about how efficiency comes into play. Say an 80% efficient 1000W PSU was supplying exactly 1000W to the system - you'd actually see ~1250W pulled at the plug! The figures I give above are measured at the plug.
Of course there's no harm in putting an extra 200W (and even more) in the PSU, but OP's question was is there any point in it. Future proofing IMO accounts for less than 1% of customers, and my thinking is that in this context it's more of an excuse than an actual reason to buy a big PSU. How many customers who buy pre-built systems actually make changes themselves at a later date? My guess would be very, very few. This here is an enthusiast community, not representative of the wider body of consumers. And using price as a reason doesn't really work... there are several 750W+ PSUs that are considerably cheaper than a top of the line 550W PSU.. If you want to compare apples to apples then you'll see the real numbers - for example, Be Quiet Dark Power Pro 850W is £60 more expensive than the 550W model. I's sooner put the same £60 into a better GPU or better CPU cooler, or extra storage space etc.
