Now that we have multiple options for medium-to-high output SFX power supplies I would like to see more case manufacturers design cases that drop ATX support and only support SFX PSUs. It's been amazing to see the designs that smaller case makers and newcomers have made when designing for the smallest cases possible and SFX PSUs have enabled them to dedicate less space for bulky ATX PSUs.
On larger cases saving an inch on the PSU is a much smaller return than it is on mITX systems. Between the higher prices and much lower availability of SFX/SFXL PSUs I don't think we'll ever see widespread adoption of them in mATX/ATX cases.
There are a couple from Lian Li, and the Kimera Industries Cerberus is nice (if you can get it), but yeah, the selection is limited. I'd love to see more SFX+mATX or SFX+ATX cases. Why not?
At this wattage, it's more like "We crammed in 800W, because we could".
Even if you assembled the most powerful mITX system, using an Asrock X299E-ITX, an i9-79xx and 1080Ti and overclocked those, you would still be inside of 600W power envelope at full load. (Going off of Coolermaster's power calculator)
Don't forget SFF cases for mATX and ATX. While 800W is not enough for the quad Titan-V beast (smallformfactor DOT net/forum/threads/kimera-industries-cerberus-the-18l-matx-usa-made-enclosure.454/page-180#post-78461), you you drop back to a mere two Titan Vs - either on an mATX board or with ITX and PCIe Bifurcation - you can cram serious compute into an even smaller case.
All the power lost due to PSU inefficiency is extra heat added to the room. When it's cold it works like supplemental furnace/etc (if electric heat is cost effective depends on what the other heat source is); in the summer it's just more heat for the AC to push out of the building.
But if a 600W PSU is pulling 90% efficiency at 400W, where as this 800W PSU is pulling 94% efficiency at 400W, the 600W would be consuming 444W, versus the 800W would be consuming 425W. A 19W difference is hardly going to result in a noticeable difference inside the case, since PSUs only expel heat.
According to Silverstone's charts the 500W SFX-L PSU is 91% efficient at a 400W load (with a 230V AC input voltage), this 800W PSU is 95 % efficient at the same load. That comes down to 439W and 421W from the wall, let's take 20W for simplicity. If the PC were to have a continuous load of 400W all year long, that makes 175.2 kWh. In my country electricity is pretty expensive, around 0.21€/kWh (probably a bit more now, 0.21 was a few years ago). 175.2 kWh would then cost €36.7, but the price difference between the 500W and 800W variant is around €100, so you'd need about 3 years of continous load at 50% to benefit from the better efficiency.
Let's also assume this PSU isn't powering a mining rig but a workstation, that gets used around 8 hours a day, that makes 9 years before the higher efficiency pays off. I doubt many PSU's are used for longer than that. Also, in most cases a 400W continuous load is a very unrealistic assumption, most pc's idle most of the time, even workstations (and this is not a server PSU). Below 20% load, both PSU's have pretty much the same efficiency. So when exactly does the higher efficiency pay off for pc's that don't have a continuous load? Pretty much never...
Much more important are the warranty and component quality, and it's not like the 800W PSU is so much better in those regards, it's not going to last longer, the chances of failure are the same. I'd even argue in favor of a 80Plus Bronze PSU instead of 80Plus Gold, because those gains in efficiency are very slim as well, but then component quality often is a bit worse and the warranty period goes down to 3 years or lower, so paying more for better quality makes sense there (for the same capacity!)
Now if you want your workstation to consume as little power as possible, be my guest and pay double the price for a PSU that only has to deliver half of its capacity at most, just don't expect the investment to pay off.
Oh when I say 175.2 kWh, I'm talking about that 20W power difference between 91 and 94% efficiency, not total consumption, that would cost a lot more than €36 of course.
I think it would be more likely be, because it is far more easy to get the titanium certification on a high powered psu. There is a reason why there are no affordable high efficiency low powerd psu's.
The article's title is like a perfect TL;DR summary. As far as SFX goes, it's a small niche product. I can't think of too many system builds that would require that much power output inside a small enough case, that also supports the larger-than-SFX physical dimensions.
1) It’s not large, but there is an enthusiast SFF market. ASRock is doing an mATX threadripper board and has an mITX x299 board, and there’s a lot of talk about bifurcation in the enthusiast sff community right now.
2) SilverStone is working on a completely passive SFX-L psu at 400w using this psu as the base.
Whatever happened to nice PSU cables? 10 years ago even cheap PSUs used beautifully sleeved cables, now even pricey PSUs have downgraded to this ribbon crap.
Ribbon cables are easier to work with, especially in tight places. Bundle sleeved cables add a lot of bulk to the cable ends and are unsuitable for SFF.
I have to correct the final conclusion in the article. I have this psu driving, a dual socket motherboard, 2 xeon v4 18 cores. 8 memory slots , with gtx 1080t. All in core g3 sfx case with additional holes drilled for eatx motherboard. In short, you can use a splitter for the 8 pin cpu cable to run dual socket motherboard.
And now, two years later, this PSU is the perfect solution for powering my mini-ITX gaming system inside the small form factor Nano S case. I'm running a 9900K, 16GB 4233Mhz DDR4, Samsung 950 Pro NVMe SSD, and EVGA RTX3080 FTW3 Ultra. The RTX3080 alone uses 450W (thanks to EVGA's latest BIOS update), so if anything I'm thinking I might actually have to upgrade the power supply if I so choose to overclock the CPU. Needless to say, no other SFX-L power supply is available today that can do what the Silverstone LTi could do two years ago ;-)
We’ve updated our terms. By continuing to use the site and/or by logging into your account, you agree to the Site’s updated Terms of Use and Privacy Policy.
Facebook
Twitter
RSS
25 Comments
Back to Article
WithoutWeakness - Thursday, January 18, 2018 - link
Now that we have multiple options for medium-to-high output SFX power supplies I would like to see more case manufacturers design cases that drop ATX support and only support SFX PSUs. It's been amazing to see the designs that smaller case makers and newcomers have made when designing for the smallest cases possible and SFX PSUs have enabled them to dedicate less space for bulky ATX PSUs.DanNeely - Thursday, January 18, 2018 - link
On larger cases saving an inch on the PSU is a much smaller return than it is on mITX systems. Between the higher prices and much lower availability of SFX/SFXL PSUs I don't think we'll ever see widespread adoption of them in mATX/ATX cases.jtd871 - Thursday, January 18, 2018 - link
WithoutWeakness wasn't talking about larger cases. He was talking about cases without support for ATX PSUs.cjb110 - Friday, January 19, 2018 - link
Not sure they can do that and still call it an ATX case, which then makes marketing a potential nightmare, that might be one reason.Valantar - Monday, January 22, 2018 - link
There are a couple from Lian Li, and the Kimera Industries Cerberus is nice (if you can get it), but yeah, the selection is limited. I'd love to see more SFX+mATX or SFX+ATX cases. Why not?jrs77 - Thursday, January 18, 2018 - link
I've got the 500W SFX-L PSU from Silverstone and it's the sweetspot for a single GPU-system imho.meacupla - Thursday, January 18, 2018 - link
At this wattage, it's more like "We crammed in 800W, because we could".Even if you assembled the most powerful mITX system, using an Asrock X299E-ITX, an i9-79xx and 1080Ti and overclocked those, you would still be inside of 600W power envelope at full load.
(Going off of Coolermaster's power calculator)
edzieba - Thursday, January 18, 2018 - link
Don't forget SFF cases for mATX and ATX. While 800W is not enough for the quad Titan-V beast (smallformfactor DOT net/forum/threads/kimera-industries-cerberus-the-18l-matx-usa-made-enclosure.454/page-180#post-78461), you you drop back to a mere two Titan Vs - either on an mATX board or with ITX and PCIe Bifurcation - you can cram serious compute into an even smaller case.jordanclock - Thursday, January 18, 2018 - link
Because conversion efficiency is best at about 50% load, so you use a PSU like this to stay within the most efficient load range.Holliday75 - Thursday, January 18, 2018 - link
How much does that translate in savings on my electric bill? How quickly would that offset the cost of a higher wattage PSU running more efficiently?Meaker10 - Friday, January 19, 2018 - link
It can help room temperatures and with a small forn factor case it could make a difference to internal temperatures.sonny73n - Friday, January 19, 2018 - link
@meaker10Huh? PSU & temperatures? What?!
DanNeely - Friday, January 19, 2018 - link
All the power lost due to PSU inefficiency is extra heat added to the room. When it's cold it works like supplemental furnace/etc (if electric heat is cost effective depends on what the other heat source is); in the summer it's just more heat for the AC to push out of the building.meacupla - Saturday, January 20, 2018 - link
But if a 600W PSU is pulling 90% efficiency at 400W, where as this 800W PSU is pulling 94% efficiency at 400W, the 600W would be consuming 444W, versus the 800W would be consuming 425W.A 19W difference is hardly going to result in a noticeable difference inside the case, since PSUs only expel heat.
Macpoedel - Tuesday, January 23, 2018 - link
According to Silverstone's charts the 500W SFX-L PSU is 91% efficient at a 400W load (with a 230V AC input voltage), this 800W PSU is 95 % efficient at the same load. That comes down to 439W and 421W from the wall, let's take 20W for simplicity.If the PC were to have a continuous load of 400W all year long, that makes 175.2 kWh. In my country electricity is pretty expensive, around 0.21€/kWh (probably a bit more now, 0.21 was a few years ago).
175.2 kWh would then cost €36.7, but the price difference between the 500W and 800W variant is around €100, so you'd need about 3 years of continous load at 50% to benefit from the better efficiency.
Let's also assume this PSU isn't powering a mining rig but a workstation, that gets used around 8 hours a day, that makes 9 years before the higher efficiency pays off. I doubt many PSU's are used for longer than that.
Also, in most cases a 400W continuous load is a very unrealistic assumption, most pc's idle most of the time, even workstations (and this is not a server PSU). Below 20% load, both PSU's have pretty much the same efficiency.
So when exactly does the higher efficiency pay off for pc's that don't have a continuous load? Pretty much never...
Much more important are the warranty and component quality, and it's not like the 800W PSU is so much better in those regards, it's not going to last longer, the chances of failure are the same.
I'd even argue in favor of a 80Plus Bronze PSU instead of 80Plus Gold, because those gains in efficiency are very slim as well, but then component quality often is a bit worse and the warranty period goes down to 3 years or lower, so paying more for better quality makes sense there (for the same capacity!)
Now if you want your workstation to consume as little power as possible, be my guest and pay double the price for a PSU that only has to deliver half of its capacity at most, just don't expect the investment to pay off.
Macpoedel - Tuesday, January 23, 2018 - link
Oh when I say 175.2 kWh, I'm talking about that 20W power difference between 91 and 94% efficiency, not total consumption, that would cost a lot more than €36 of course.Foeketijn - Friday, January 19, 2018 - link
I think it would be more likely be, because it is far more easy to get the titanium certification on a high powered psu. There is a reason why there are no affordable high efficiency low powerd psu's.The Benjamins - Thursday, January 18, 2018 - link
It only having 1 4+4 EPS sucks, you can't use this for the AsRock X399M board in a CaseLabs Bullet BH4.PeachNCream - Thursday, January 18, 2018 - link
The article's title is like a perfect TL;DR summary. As far as SFX goes, it's a small niche product. I can't think of too many system builds that would require that much power output inside a small enough case, that also supports the larger-than-SFX physical dimensions.Lau_Tech - Thursday, January 18, 2018 - link
These "stuff i found in my attic" reviews are really blockbuster stuff, eh?masteraleph - Friday, January 19, 2018 - link
1) It’s not large, but there is an enthusiast SFF market. ASRock is doing an mATX threadripper board and has an mITX x299 board, and there’s a lot of talk about bifurcation in the enthusiast sff community right now.2) SilverStone is working on a completely passive SFX-L psu at 400w using this psu as the base.
cbm80 - Friday, January 19, 2018 - link
Whatever happened to nice PSU cables? 10 years ago even cheap PSUs used beautifully sleeved cables, now even pricey PSUs have downgraded to this ribbon crap.meacupla - Saturday, January 20, 2018 - link
Ribbon cables are easier to work with, especially in tight places.Bundle sleeved cables add a lot of bulk to the cable ends and are unsuitable for SFF.
sharath.naik - Monday, February 26, 2018 - link
I have to correct the final conclusion in the article. I have this psu driving, a dual socket motherboard, 2 xeon v4 18 cores. 8 memory slots , with gtx 1080t. All in core g3 sfx case with additional holes drilled for eatx motherboard. In short, you can use a splitter for the 8 pin cpu cable to run dual socket motherboard.Ninjawithagun - Thursday, November 12, 2020 - link
And now, two years later, this PSU is the perfect solution for powering my mini-ITX gaming system inside the small form factor Nano S case. I'm running a 9900K, 16GB 4233Mhz DDR4, Samsung 950 Pro NVMe SSD, and EVGA RTX3080 FTW3 Ultra. The RTX3080 alone uses 450W (thanks to EVGA's latest BIOS update), so if anything I'm thinking I might actually have to upgrade the power supply if I so choose to overclock the CPU. Needless to say, no other SFX-L power supply is available today that can do what the Silverstone LTi could do two years ago ;-)