PSU Fundamentals & Recommendations
well, now that I have you here I might as well ask your advice (and the advice of anyone else here who wants to give it).
This thread details a computer I'm building and that is going to be placed in our bedroom. After going from the silentium case to an Antec SLK3000B based on advice, I now need to find a power supply. I guess the Fortron isn't good enough, but I found a norwegian webshop that sells the Antec Smartpower 400W (pre-installed in the case) and a Nexus NX-4090 400W.
Which would you say is best for my system? According to the recommendation, the Antec gets the best score, but according to the dB listing in the reviews, the Nexus is best...
This thread details a computer I'm building and that is going to be placed in our bedroom. After going from the silentium case to an Antec SLK3000B based on advice, I now need to find a power supply. I guess the Fortron isn't good enough, but I found a norwegian webshop that sells the Antec Smartpower 400W (pre-installed in the case) and a Nexus NX-4090 400W.
Which would you say is best for my system? According to the recommendation, the Antec gets the best score, but according to the dB listing in the reviews, the Nexus is best...
I think SPCR is very wise to temporarily withdraw its recommendation from the NeoHE 430 until such time as the current problems with various makes of motherboards are satisfactorily resolved. A lot of the kudos that comes with an SPCR recommendation is derived from the fact that recommended products are generally of a very high quality with little in the way of compatibility or build quality problems (like the Seasonic S12 range for example). IMO the NeoHE has not yet shown it can live up to these high standards consistently.Why not add the Neo HE to the list somewhere? It was reviewed separatly.
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In light of these power numbers at Tom's, I think we should note the increased power draw of overclocking.
OCZ GameXStream 600W & 700W
Could we get reviews of the OCZ GameXStream 600W & 700W PSUs please? Especially vis-a-vis the Seasonic S12 600W. Just that I've read many reviews that wax lyrical about how quiet the new OCZ PSUs are, especially for such a powerful PSU. Of course, what I would love to know is how quiet are they in the eyes of SPR analysis and vs the competition? Also, given that a 120mm fan mod looks easy on the OCZs, a) is it? with a Nexus of Scythe S-Flex for example? and b) how would that affect it and its standings for noise?
Any comments to this note appreciated
Any comments to this note appreciated
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Why bother? The S12-600 is about the same price as a GameXStream 600.jaganath wrote:Given that the OCZ GameXStream fan spins almost twice as fast as the S12-500 fan at all points along the output curve, in stock form it's no contest noise-wise. However OCZ quote 83% efficiency on 230V AC, so there is probably good potential for a fan swap to improve noise.
OCZ vs Seasonic
Thanks Oleg and others. BTW Oleg, have you got a link for your graph or was it constructed yourself? Thks.
I guess the Seasonic is convincing given the backing it has by so many here - shame it hasn't got nice sleeved cables but the noise factor is more important.
I guess the Seasonic is convincing given the backing it has by so many here - shame it hasn't got nice sleeved cables but the noise factor is more important.
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Article with this graph will be published at xbitlabs.com... mmm... may be at the end of august Yes, it was constructed by myself
Actually, OCZ GameXStream made by FSP and almost identical with FSP Epsilon, but Epsilon is much quieter. I asked FSP Group did they change fan speed controller in all their Epsilons (new revision?) or for OCZ only, but there's no answer yet.
Actually, OCZ GameXStream made by FSP and almost identical with FSP Epsilon, but Epsilon is much quieter. I asked FSP Group did they change fan speed controller in all their Epsilons (new revision?) or for OCZ only, but there's no answer yet.
Re: OCZ vs Seasonic
Seasonic upgraded the S-12 series quite recently, the PSUs now have sleeved cables, here's a pic from the SPCR review of the S12-330.Noli wrote:I guess the Seasonic is convincing given the backing it has by so many here - shame it hasn't got nice sleeved cables but the noise factor is more important.
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Of course. Check any SPCR power supply review. We've review a lot of them, many of the best, imo.msde wrote:I've always tried to approach silent computing by attacking the source of the problem, heat. Or, in other words, power consumption. Is there any way to tell whether one recommended PSU is more efficient than another? Or should I just grab an 80+ and call it a day?
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Minor update, just to the recommended tables.
Thanks for the update
Just checking with regard to PFC and energy efficiency on the fanless Silverstone ST30NF:
Just checking with regard to PFC and energy efficiency on the fanless Silverstone ST30NF:
However on the previous page of Power Supply Fundamentals & Recommendations:... along with Active PFC, a big plus for energy efficiency.
Does PFC make a power supply more efficient? No , the power factor correction is usually applied by an input circuit which uses a small amount of input power. With two PSUs that are identical, equipping one with PFC will cause a typical efficiency drop of 2~4% ... APFC is usually found on higher quality PSUs, but the two are not intrinsically related.
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HueyCobra --
You're right, that was probably confusing for lots of people.
The text "...a big plus for energy efficiency" has been removed, and the answer to the question Does PFC make a power supply more efficient? has been expanded:
You're right, that was probably confusing for lots of people.
The text "...a big plus for energy efficiency" has been removed, and the answer to the question Does PFC make a power supply more efficient? has been expanded:
I also took a closer look at the discussion of efficiency at the beginning of the article... and found that nowhere is efficiency explicity defined. I've corrected that oversight with the following, on the second page:Not in the normal way that power supply efficiency is defined, which is the power loss (to heat) as a percentage of total AC input in AC-to-DC conversion. However, in the sense that Apparent AC power (VA) is lowered, PFC does reduce energy consumption.
Power factor correction is applied by an input circuit which uses a small amount of input power. With two PSUs that are identical, equipping one with PFC will cause a typical efficiency drop of 2~4%. Many PSUs that have Active PFC also have high efficiency, as APFC is usually found on higher quality PSUs, but the two are not intrinsically related.
The table mentioned above shows the power lost as heat at different efficiency levels.What is efficiency in a power supply? It is defined as the power loss in AC-to-DC conversion, expressed as a percentage of total AC input power. For example, a power supply that requires 100W AC input to produce 70W DC output has an efficiency of 70%. In this example, 30W is lost as heat within the PSU. A power supply that requires 100W AC input to produce 80W DC output has an efficiency of 80%. 20W is lost as heat. The 10W difference in these examples seems trivial. However, at higher output levels, differences in efficiency becomes quite significant in terms of how much energy is lost as heat, as the table below shows. The ideal efficiency is 100%, where AC input and DC output are the same, and there is no loss to heat in the power supply.
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Aug 31/06 update
Aug 31/06 update-- Updated much of the text on Intel PSU guidelines based on latest Power Supply Design Guide for Desktop Platform Form Factors (Revision 1.0 - June 2006). Also expanded discussion on multiple 12V lines, efficiency, power factor correction, etc.
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This image is from page 4 of one of the classic articles on SPCR.
I wonder if that section shouldn't be modified. It seems that average newcomers to SPCR are going to be most concerned with the 100 to 200 watt range.
If you comb the various SPCR articles and make a seasonic to seasonic comparison instead of seasonic to enermax you see:
At 90w the S12-430w has the best effeciency
At 150w the S12-430w has the best effeciency
at 200w the S12-330 and S12-500 tie for best efficency but the s12-430 is so close it's a non issue.
Code: Select all
Model Output (W) 65 90 150 200 250 300 400 500 600
S12-330 Efficiency 75.5% 77.9% 80.3% 82.0% 80.9% 79.9% **
S12-430 78.3% 80.5% 81.6% 81.8% 80.5% 79.6% *
S12-500/600 75.1% 78.0% 81.2% 82.0% 81.8% 81.1% 79.0% 79.7% 78.9%
Enermax 600 69.4% 73.8% 78.9% 80.2% 80.5% 80.3% 78.8% 76.5% 73.6%
(Enermax NoiseTaker II (Revision 2.2))
Or at least reflect what it truly is? Because all that chart does is compare an efficient PSU with a less effecient PSU. I.E. too many variables and not enough controls.
Would it be better to compare a cheap 300w PSU with a cheap 600w PSU or to compare S12-330 to S12-600? I don't know, but I have always found that part of the article to not hold up when I read the reviews of better power supplies.
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The two items were chosen for comparison because it shows clearly what is meant by correct PSU sizing, which is the main thrust of the text in that section. Both of the PSUs are high efficiency. Lots of people have posted (and continue to post) in the SPCR forums about whether they should be getting a 500W or 600W model when in fact the details of their systems suggest maximum peak loads of <300W. This is precisely what the comparison was meant to address. I don't see how and why you think it does not hold up. It's a simple comparison.dhanson865 wrote:I wonder if that section shouldn't be modified. It seems that average newcomers to SPCR are going to be most concerned with the 100 to 200 watt range....
...Shouldn't the chart and discussion on that page of the article reflect the sweet spot of effeciency around the 400w rating area? Or is the margin of error in the S12 series articles too close?
Or at least reflect what it truly is? Because all that chart does is compare an efficient PSU with a less effecient PSU. I.E. too many variables and not enough controls.
Would it be better to compare a cheap 300w PSU with a cheap 600w PSU or to compare S12-330 to S12-600? I don't know, but I have always found that part of the article to not hold up when I read the reviews of better power supplies.