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Are PSU's a rip off ?
- Thread starter pegasus1
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Thats on the assumption that its power distribution curve is linear which I very much doubt, especially considering real world cross-loads - also efficiency is also dependent on the load going through the PSU at the time...Nullvoid said:
Got to agree with that - I plumped for an OCZ Powerstream 520W since it had a single rail as i think multiple rails can potentially affect overclocks due to the way they equally distribute power over the rails and to components that just dont need that fraction of power...drunkenmaster said:
pd3ud0
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Your PSU is by far the most important bit in your rig. A high-quality one will have premium components in it and its manufacturer will probably be selling it for a far narrower profit margin than Intel will be selling those cheap-as-chips (no pun intended) E2160s, simply because they can pump out thousands of them out of their fabs - the manufacturing cost for each chip is infinitessimally small, the money it cost mostly goes to pay for the cost of researching and developing it, whereas a quality PSU costs real money PER UNIT to make on top of the R&D cost for it.
Well the Toughpower has been shown to sustain 80%+ efficiencies right the way through its meaningful range of output (ie 250w to max. If someone bought one to power a rig that drew less than 250w at full load, well there's no hope for them 
)
Concerning your other point, could you just elaborate it a bit (I'm currently trying to learn more about power supplies myself and it went over my head
)?
)Concerning your other point, could you just elaborate it a bit (I'm currently trying to learn more about power supplies myself and it went over my head
)?
i think this thread (not mine) is about whether PSU's are worth the cost. not whether a good psu is worth having over a lesser rated one, but in general if the cost is justified. I dont think he is saying "I dont want to pay "£100 for a psu therefore i might buy whatever £30 gets me"
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One thing I'm wondering is whether any manufacturer will ever be brave enough to offer Connected Equipment Warranties...
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> Qtec f.t.w <
mame said:
I think the cost is very much justified. Once a good psu is installed you should hopefully never have to think about it again, and it will keep your system running along nice and stable for as long as you ask it to. That might not earn it the recognition and praise that is typically lavished on a new graphics card or processor, but I still think that reassurance of consistent and reliable performance makes it worth every penny spent.
Basically the majority of tests only really look at maximum single voltage loads or the efficiency on these loads (i.e. how much can the 12v rail take and how efficient is this and at what temperature)...Nullvoid said:Well the Toughpower has been shown to sustain 80%+ efficiencies right the way through its meaningful range of output (ie 250w to max. If someone bought one to power a rig that drew less than 250w at full load, well there's no hope for them
Concerning your other point, could you just elaborate it a bit (I'm currently trying to learn more about power supplies myself and it went over my head
a lot of manufacturers do this when actually rating their PSUs (generally at 50C though PCP&C generally say they do it at 25C IIRC) but the results arent really meaningful in the real world because PSUs have to sustain wattage across several DC voltages and therefore are never realistically outputting 100% on a single DC voltage.
Because of this cross load (dealing with more than one voltage at the same time) the actual output power will never hit the rated output (which is why the maximum combined output rating is always less than the addition of the wattages on the single voltages). So when you take into account the related loads on 3.3v, 5v and 12v you just will never get near the rated wattage that manufacturers describe and what most simple load tests check.
The function of this can be plotted on a power distribution/cross loading graph where each of the DC voltages (generally 12v v 5v+3.3V) become the axis and the maximum wattage that can be sustained in those conditions. Though since these deal with ideal conditions (temperature as a constant) they arent 100% accurate...
Look at p15-p19 for examples: http://www.formfactors.org/developer\specs\ATX12V_PSDG_2_2_public_br2.pdf
All I was basically saying is that when you refer to 40% load you arent really being that specific and such a generalisation really doesnt actually give you a great idea how good the PSU is (or your comparison of) - if I was being facetious then the figures you quoted from that review could be considered inaccurate as you wouldnt know how much of that load was being attributed to the 12v and therefore how much the voltage deviated (it doesnt even consider ripple/noise)...
P.S. Apoligises if that makes little sense, its been a while since Ive had a look into it and only did due to the PFC issue and the introduction of multiple rails and why it was purported they were so 'good' (ATX 2.2 spec IIRC)...
ps3ud0
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Jihad said:
Yes if you go for highest price of anything. I think he's saying why is a mid-range PSU £60-70?
This reminds me of (completely off topic, sorry) mobile phone cameras. A major mobile phone manufacturer said that they could produce an 8 megapixel camera phone now if they wanted and yes it would probably sell out but why should they? what would they do then?? Better for them to produce a 1mp then a 2mp then a 3mp then a 4mp then a 5mp then a 6mp then a 7mp then an 8mp (dont quote me on exact resoluitons) phone. Keeping the interest and price high. He is saying why shouldnt he be able to buy an ok PSU for a good price when is must not cost a lot to produce. Oh im going to get it for this post!!!
OK well I think I've got your drift! I remember seeing something very similar to that style of graph in some power supply reviews xbitlabs did.
By the way, the figures I was using were lifted (perhaps erroneously) from this page of jonnyguru's toughpower review: http://www.jonnyguru.com/review_details.php?id=107&page_num=3
I had always thought his testing was super thorough (to the point of being anal about it) but perhaps that isn't the case.
And my waffle about a 80% load being halved on the toughpower was intended just to mean the 12v rails alone. I can see that even then it is still a gross oversimplification. I guess my reasoning was that both models almost appear to be designed with operation under crossload conditions (I know there are two types, but umm, where the majority of the power is on the 12v rails) in mind. Their specs suggest the corsair is designed to be able to output 600w (96.77%) on its 12v rails and the toughpower can output 1195.85W (99.65%). Unreachable in practical terms I know, but still interesting.
Speaking of 12v rails. You were saying that power supply technology advancement has been pretty stagnant, but surely a pretty revolutionary development would be to get all PC components working with a 12v supply instead of this hodgepodge of different values (3.3, 5, -5, -12 etc...). Is such a thing even possible?
By the way, the figures I was using were lifted (perhaps erroneously) from this page of jonnyguru's toughpower review: http://www.jonnyguru.com/review_details.php?id=107&page_num=3
I had always thought his testing was super thorough (to the point of being anal about it) but perhaps that isn't the case.
And my waffle about a 80% load being halved on the toughpower was intended just to mean the 12v rails alone. I can see that even then it is still a gross oversimplification. I guess my reasoning was that both models almost appear to be designed with operation under crossload conditions (I know there are two types, but umm, where the majority of the power is on the 12v rails) in mind. Their specs suggest the corsair is designed to be able to output 600w (96.77%) on its 12v rails and the toughpower can output 1195.85W (99.65%). Unreachable in practical terms I know, but still interesting.
Speaking of 12v rails. You were saying that power supply technology advancement has been pretty stagnant, but surely a pretty revolutionary development would be to get all PC components working with a 12v supply instead of this hodgepodge of different values (3.3, 5, -5, -12 etc...). Is such a thing even possible?
That wont 'ever' happen considering the investment thousands of companies in present technology and the power it takes to run. Just be impossible logistically and probably only happen with a new form factor (though I doubt it makes financial sense - if it aint broke why fix it mentality)...Nullvoid said:
For example, laptop power supplies only output 1 DC voltage which gets reconverted by the individual components (Im unsure where exactly) to the DC voltages it requires...
I dont think your analogy really works - theres no demand for such high powered PSUs (well not in ATX, perhaps SFX) and I doubt they are holding back new technology for the sake of it. Indeed ignoring all the manufacturer power requirements the latest tech doesnt demand the increase in wattage that we have seen from PSUs lately. Yes the high-end PSUs are very expensive, but its not like the bottom end is...mame said:
What evidence do you have on the fact they dont cost a lot to produce - they definitely do per unit compared to a CPU - perhaps they dont do as many whizz bangy things or as technically advanced, but I dont think its really out of proportion that a decent PSU costs around £50 while the cheapest C2D is the same - especially considering that PSU would probably more than adequately cope with it...
Really dont see the problem...
ps3ud0
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tbh, ive not read through the entire topic, so my point might be invalid, but here it is anyway.
1) there expensive because the testing, build and overal quality is better
2) would you run a F1 car with some cheap tires?
3) would you rather go for stability over cost effectiveness?
when i had to choose my psu, i chose wisely, i never ever buy a cheap psu, as its simply one of the most dangerous parts there is in a pc, if it goes, it can take out everything (in some cases) so when people pay extra for there psu, there buying reassurence (cnt spell).
ags
1) there expensive because the testing, build and overal quality is better
2) would you run a F1 car with some cheap tires?
3) would you rather go for stability over cost effectiveness?
when i had to choose my psu, i chose wisely, i never ever buy a cheap psu, as its simply one of the most dangerous parts there is in a pc, if it goes, it can take out everything (in some cases) so when people pay extra for there psu, there buying reassurence (cnt spell).
ags