Help finding power supply with dual 8-pin EPS connectors?
- Thread starter mattlach
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Two EPS is easy. Three EPS on the other hand is a little tough. You can buy an adapter cable that will pull 4+4 eps off of the 6 PIN VGA cable. It essentially swaps power and ground so that you don't make magic blue smoke.
One of these is what i use for my x9drg that need 2.5 8 pin EPS connectors:
CB-6M-44F 6pin PCI-EX Male to 4+4pin EPS female,12in
One of these is what i use for my x9drg that need 2.5 8 pin EPS connectors:
CB-6M-44F 6pin PCI-EX Male to 4+4pin EPS female,12in
The reason to try not to split is that each split / each additional connection adds resistance and in the case of splitting pc/server power there's often very poorly made connections / adapters which now add an additional problem of them 'coming off' and starting a fire, melting the connector, etc...
As someone else said make sure the connections don't get hot you don't want them overheating and melting in the future, and then make sure they're snug... and to be extra safe I use electrical tape to connect my extensions, splitter, etc... just so I know they aren't coming apart.
FWIW I am running at-least 2 or 3 splitters in my home all in one to accommodate so many drives in a tower case
with custom brackets, and drives (SSD mostly) shoved everywhere. At one point I had 8x HDD, 17x SSD and 2x 2.5" NVME crammed into this mid-tower... I think all but 4 were direct connect (no backplane) so that was a ton of adapters for power. I've reduced it a good bit now (2 systems), but still run electrical-taped splitters/adapters where I needed too.Also, as a side note I've gotten around 5+ boards from ebay that had splitters still attached for the 4 pin power from molex, so it's somewhat common on certain boards in server configs too.
Be sure to examine the splitters carefully sometimes the wires aren't the only issue and the plastic is brittle and BAD for where it's used and wil simply snap and crack not flex as it should, etc...
I just did my built with an S2600cp2j board. Had to search a little about psu beforehand. I thought about being cheap but it's way too much of a risk to buy psu with single eps/cpu connector and get adapter. Not worth it IMO even for non mission critical cases. eps connectors can draw a lot more than a regular 6 pin or something even more than the 150w that the 8pin pcie connector can provide. you end up stressing out your psu and risk hardware failure for a saving of a few dozen bucks?
If you really want to be cheap, you can still get a proper gold plus 1120w Lenovo d30 psu that has proper two eps connectors for around $40:
54Y8845 IBM LENOVO THINKSTATION 1120W SERVER POWER SUPPLY 0A37782
Note that one of the eps cable is really short so you need to get some extension cables like these:
8 Pin Male To Female ATX EPS Power Supply PSU Extension Cable 12v extender AB
If you really want to be cheap, you can still get a proper gold plus 1120w Lenovo d30 psu that has proper two eps connectors for around $40:
54Y8845 IBM LENOVO THINKSTATION 1120W SERVER POWER SUPPLY 0A37782
Note that one of the eps cable is really short so you need to get some extension cables like these:
8 Pin Male To Female ATX EPS Power Supply PSU Extension Cable 12v extender AB
I have been wrestling with this recently.
I bought the 4-pin Molex to 8 pin adapters for an older power supply that I use on my bench.
The Supermicro I got from T-minus (Thanks!) recommends both 8 pin AND 4 pin but considers the 4-pin optional.
A good modular power supply and extra cables is so much ... I just bought a used CSE-825 Supermicro case with power supply.
Yes, it costs more than a $100 power supply but I got the case, backplane, caddys, cables and rails shipped for $190
It arrives next week and I am just hoping that they include 2 8-pin power on the supply. If lucky and get the 4-pin as well.
I could not find the exact recommended Supermicro CSE-825 variant for under $300 so I am hoping this will do.
I was just using old consumer boards in a cheap $60 4U rosewill case. I am now upgrading to used datacenter equipment.
I bought the 4-pin Molex to 8 pin adapters for an older power supply that I use on my bench.
The Supermicro I got from T-minus (Thanks!) recommends both 8 pin AND 4 pin but considers the 4-pin optional.
A good modular power supply and extra cables is so much ... I just bought a used CSE-825 Supermicro case with power supply.
Yes, it costs more than a $100 power supply but I got the case, backplane, caddys, cables and rails shipped for $190
It arrives next week and I am just hoping that they include 2 8-pin power on the supply. If lucky and get the 4-pin as well.
I could not find the exact recommended Supermicro CSE-825 variant for under $300 so I am hoping this will do.
I was just using old consumer boards in a cheap $60 4U rosewill case. I am now upgrading to used datacenter equipment.
Yeah, where can you find one? the only one i know readily available is a lenovo d30 psu:
Lenovo D30 1120W PSU
Kind of wondering since what are you suppose to replace in a d30 if you want something generic
Me too on my S2600CP2J
But what we are talking about is a psu with 2x 8pin (or 4+4) CPU with also a 24 pin ATX AND an additional 4 pin power. This is what Lenovo D30 and dell t5500 uses. Look here:
Lenovo D30 1120W PSU
Have you seen any other standard PSU with that? I haven't
The only thing i can think of is getting a psu with 20+4 pin ATX with 2x 8pin CPU. Then buy a 20pin to 24 pin adapter (ATX 20 Pin PSU to Mini HP ATX 24 Pin Connector Adapter).
WP - I agree. For power supplies such the EVGA SuperNove 850 B2 with 2 - 4 x 4 CPU connectors, there are adapters that will convert a 4-pin CPU connector to an 8-pin. Given a large enough 12v rail on the PS, one of these might be sufficient, particularly if it is used on the hardwired connector lead rather than the modular one. It seems there could be a chance of some extra heat at the PS connection due to the extra current flow through a connector.
Didn't an earlier thread get into this in pretty much detail (if not some mildly warm disagreements)?
Didn't an earlier thread get into this in pretty much detail (if not some mildly warm disagreements)?
Yeah, there are certainly a lot of ways to make some conversion. The problem is the lack of additional info such as how much power draw the dell and lenovo makes from each of those main connectors.
I personally like going the way of getting a psu with a 20+4 pin ATX connector and then getting a 20 pin to 24 pin adapter cable onto the 20pin atx connector. you might also need an extension cable onto the 4 pin. This leaves you with symmetric loads on the 2 8 pin (or 4+4) CPU/EPS connectors. if you get an 4 pin to 8 pin adapter onto one of the 4 pin on the 4+4, it leaves you with asymmetric CPU connector loads. Again, might not really matter if both the ATX as well as the CPU/EPS connectors are all from the same rail.
Or as RobertF suggested above, you can pull additional power from PCIe cable with this adapter as long as you don't use more than 75w with it and don't need that for a video card:
CB-6M-44F 6pin PCI-EX Male to 4+4pin EPS female,12in
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I ended up buying a CSE825 that came with a power supply.
However, it only had 1 4-pin and so now I need to find a 4-pin splitter.
The 2 x 8-pin seem like enough to run the system but might as well send power to both 4-pin connectors.
All this talk makes me think I should disconnect the 4 pin that I have connected. This is not symmetric.
However, it only had 1 4-pin and so now I need to find a 4-pin splitter.
The 2 x 8-pin seem like enough to run the system but might as well send power to both 4-pin connectors.
All this talk makes me think I should disconnect the 4 pin that I have connected. This is not symmetric.
The evga 850 b2 has (20+4) pin ATX connector and 2x (4+4) pin CPU/EPS connector.
The Lenovo D30 psu has 24 pin ATX connector and an additional 4 pin connector as well as 2x 8 pin CPU/EPS connectors.
So does the CSE825 psu has (20+4) pin ATX and 2x 8 pin CPU/EPS connector?
I'm not an electrical engineer, but there's plenty of information available on the web. Let's take a more detailed look at this "symmetric" issue.
Short version:
On a single 12v rail power supply, ALL the 12v outputs are connected and tapped off of a single regulated circuit inside the ps. The "symmetry" being discussed does not exist unless there are multiple 12v rails. I think the only issue is whether a splitter has so much current running through it to generate enough heat to cause a connector failure.
Long winded version:
In a power supply (like the EVGA SN 850 b2) that has a 4+4 CPU connector hardwired into the unit, there is no connector to heat at the power supply. The modular 4+4 would have the extra connection into the power supply/ So if a splitter would be used on the hardwired 4+4, there would be one connector between the CPU connector and the mb. That would be the same as the modular without a connector. The wire itself, in the length needed for the connection, is capable of handling plenty of 12v current and is not a factor. Since ALL the 12v current is coming from a single regulated circuit / "wire" in the power supply, it doesn't matter how many wires or splitters are connected downstream. The ps will simply see the sum total load of all the connections.
This is just my analysis. I've made mistakes in the past and I'm seriously interested in reading information to the contrary.
Short version:
On a single 12v rail power supply, ALL the 12v outputs are connected and tapped off of a single regulated circuit inside the ps. The "symmetry" being discussed does not exist unless there are multiple 12v rails. I think the only issue is whether a splitter has so much current running through it to generate enough heat to cause a connector failure.
Long winded version:
In a power supply (like the EVGA SN 850 b2) that has a 4+4 CPU connector hardwired into the unit, there is no connector to heat at the power supply. The modular 4+4 would have the extra connection into the power supply/ So if a splitter would be used on the hardwired 4+4, there would be one connector between the CPU connector and the mb. That would be the same as the modular without a connector. The wire itself, in the length needed for the connection, is capable of handling plenty of 12v current and is not a factor. Since ALL the 12v current is coming from a single regulated circuit / "wire" in the power supply, it doesn't matter how many wires or splitters are connected downstream. The ps will simply see the sum total load of all the connections.
This is just my analysis. I've made mistakes in the past and I'm seriously interested in reading information to the contrary.
While upgrading my main rig, I also needed a fully modular PSU with 2 x EPS 12V connectors for my motherboard. I opted for the 80+ Gold Corsair RM850i after reading this review score. The EVGA Supernova 850w G2 was my second choice.
So it looks like the 850 B2 is single rail by newegg site. guess wont have to worry about the asymmetric loads on the two CPU cable since they re all from one rail like bill said. i like their 5 yr warranty too. that and corsair 10 yr warranty.
A great deal of PSUs these days have a single 12V rail design. Where even 5V and 3.3V are tapped off from (via DC to DC conversion). It simplifies PSU design.
The EVGA SuperNova is also a single 12V rail design and the cable with the two EPS connectors are on the same cable.
The EVGA SuperNova is also a single 12V rail design and the cable with the two EPS connectors are on the same cable.