May 11, 201610 yr Hi guys, Quite new around here but have been popping in and out for the last 6 months... I've trawled through the existing posts on hardware advice and builds couldn't find a good solid recommendation for my disk\peripheral set up and was wondering whether anyone could help? This is the kit i currently have ready to be re-purposed: 1 x Case 424 chassis (Stock fans at the mo! ) 1 x Supermicro X9SCM-F Mobo 1 x Xeon E3-1245 (95w with iGPU) 3 x Dell H200 6gb/s (unflashed at the moment!) 4 x Molex 4-pin to 3-way splitter. 24 x 2TB Disks (Mix of 7200rpm and 5900rpm, mix of brands.) 1 x Samsung EVO 500gb Still needing: 6 x 8087 -> 8087 cables 1 x PSU --- My questions are! 1. Anyone have a good link to 6 x cheapy 0.5m 8087 to 8087 cables in the UK?? 2. What model\size power supply should i go with to accomodate for my kit list? I was drawn to the Corsair TX650 but a little concerned it may come up a little underpowered? Due to having a mix of disks and 3 x HBA's and a 95w CPU i'd like to future proof when i dump the 2tb disks to be able to cover any future disk upgrades. All the examples i could see were for 20+ green disks which seemed a little light on the power usage in comparison. If anyone can list off what they've had good results with going forward that would be super handy!! 3. If i were to flash the H200 HBA's with a firmware allowing staggered spin up could i hedge my bets with the 650w supply do you think? Or will the parity check get me?! 4. Any suggestions on upgrading the 12cm and 8cm fans on these rackmount chassis? Was hoping to move them all to PWM as their current 4 pin molex i believe? Any advice/pitfalls would be great at this stage in the build!
May 12, 201610 yr Anyone got a good PSU suggestion??? lol What's the demand you will have in watts for the whole system?. I would recommend a Platinum PSU if it will be running 24/7, also single rail is preferred for unRAID
May 12, 201610 yr Author Hi there! Yeah I was eyeing up a single rail Corsair 650 as people running 24 drives have had good results... my fear is that a lot of the disks are 7200 and i run 3 hba's....
May 12, 201610 yr 650w is enough, I have two 20 disks servers with Corsairs TX650w, IIRC during power up power usage tops at ~250W for a few seconds.
May 12, 201610 yr Wattage is at the plug is irrelevant. What you're seeing is 250W @ 110 volts. What's important is the max current draw in amps on the individual rails EG: Using the TX650w (Max current on 12v line is 52a). Populate it with 20 x 3TB Seagates ST3000DM001, and at start up and parity check / rebuild you're drawing 20 x 2.5a (according to the spec) 50 amps. Now out of the remaining 2 amps, you've got to power the CPU, add on cards, etc. While it would probably be ok, you are over driving the PSU for those periods when all drives have to spin up concurrently, and that is going to impact the life and/or reliability of the PSU over time (not to mention that PSU's do age and as they get older they cannot supply their rated amps anymore. IE: in 2-3 years time maybe the supply can only handle 48A on the 12v rail) And if you're going to run that borderline on the 12v rail, then you also should really add up the amps on the 5v line just to be sure. If you use green drives that only draw 2a then you'll be fine. My point is that when spec'ing a power supply you've got to look at what is hooked up to it on YOUR system, and add leeway for expansion / aging / etc
May 12, 201610 yr EG: Using the TX650w (Max current on 12v line is 52a). Populate it with 20 x 3TB Seagates ST3000DM001, and at start up and parity check / rebuild you're drawing 20 x 2.5a (according to the spec) 50 amps. 2.5 Amps is during spin up only, most disks use less than 1amp in use, like during a parity check. My server uses < 180w during a parity check, although i use green drives only.
May 12, 201610 yr EG: Using the TX650w (Max current on 12v line is 52a). Populate it with 20 x 3TB Seagates ST3000DM001, and at start up and parity check / rebuild you're drawing 20 x 2.5a (according to the spec) 50 amps. 2.5 Amps is during spin up only, most disks use about less than 1amp in use, like during a parity check. My server uses < 180w during a parity check, although i use green drives only. I understand that. My point is that spin ups draw the most power and you can't use staggered spin up with unraid to use a lower spec psu. Why play with fire when on my example you are running the single most component in the entire server out of spec Sent from my LG-D852 using Tapatalk
May 12, 201610 yr I understand that. My point is that spin ups draw the most power and you can't use staggered spin up with unraid to use a lower spec psu. Why play with fire when on my example you are running the single most component in the entire server out of spec I'm not, wd green disks peak at 1.73A x 20 = 34.6, the remaining is more than enough for the rest, especially since peak power lasts 2 or 3 seconds. But I do take your point and agree that if the OP is going to use 24 x 7.2k rpm it should go a little higher, like 750w.
May 14, 201610 yr It should, but if most your disks are 7.2k rpm Seagates it may be a little close, check the max peak power of your disks, add them up plus about 15amps for cpu/board/fans/etc and look for one with enough power, e.g, Corsair RM750X has 62.5A.
May 18, 201610 yr Author Which leads me to my next question... PSU's like the Corsair RM750X that have 62.5A on the 12v line only ever terminate to 2 molex connectors.... That sounds worrying... If you look at the spec of 18awg wire (which most splitters seem so be) then the sustained maximum ampage is around 16 amps! so surely powering say my 12 molex connectors on my back plane from 2 molex connectors pulling potentially 48 amps (briefly) Is just asking for trouble?? Can anyone recommend any good splitters for getting around this issue? I know that the length of splitter comes into play and the fact that the power is a brief surge but then numbers dont seem to add up... 12v single rail (62amps!) ---> 2 molex connectors (Carrying all power accross them!) = FIRE?? I was looking at these splitters, which benefit from being short but are still only 18awg... thoughts from people running 24 bay cases? Whose the go to? http://www.moddiy.com/products/Top-Quality-18AWG-Molex-to-3-x-Molex-Cable-Splitter.html
May 18, 201610 yr Which leads me to my next question... PSU's like the Corsair RM750X that have 62.5A on the 12v line only ever terminate to 2 molex connectors.... That sounds worrying... If you look at the spec of 18awg wire (which most splitters seem so be) then the sustained maximum ampage is around 16 amps! so surely powering say my 12 molex connectors on my back plane from 2 molex connectors pulling potentially 48 amps (briefly) Is just asking for trouble?? Can anyone recommend any good splitters for getting around this issue? I know that the length of splitter comes into play and the fact that the power is a brief surge but then numbers dont seem to add up... 12v single rail (62amps!) ---> 2 molex connectors (Carrying all power accross them!) = FIRE?? I was looking at these splitters, which benefit from being short but are still only 18awg... thoughts from people running 24 bay cases? Whose the go to? http://www.moddiy.com/products/Top-Quality-18AWG-Molex-to-3-x-Molex-Cable-Splitter.html Using splitters doesn't fix that as the power is still carried through the wires before the splitter. Use SATA power to molex adapters on the sata lines to get the power you need
May 19, 201610 yr Author Thanks Squid any reason to bite off the sata connectors and not the molex? surely if its a single rail psu it dosn't really matter does it? only reason i ask is that i've just ordered 2 of the splitters listed in the link a few posts up... under the impression it all comes off the same rail?
May 19, 201610 yr Yes but if you say (exaggerated) 6 splitters all on the same wires coming from the ps your going to exceed that wires maximum capacity. IMO avoid splitters at all costs. Hence why I suggest a sata to Molex adapter as your going to have a ton of unused sata power connectors (generally on separate lines coming from the ps) Sent from my LG-D852 using Tapatalk
May 19, 201610 yr Author Im a little confused. My chassis's backplane terminates to 12 molex connectors.. It is single rail and modular it has 2 cables with molex conectors and 2 cables with sata connectors. I was planning on running a 6 way molex splitter off each molex cable ... is there a benefit to running 2 x 6 way sata splitters of the 2 sata cables instead?
May 19, 201610 yr No problems doing that if you don't mind exceeding the power rating of the wires feeding that 6 way splitter who's quality is going to be marginal at best Sent from my LG-D852 using Tapatalk
May 19, 201610 yr Just for reference, the rated maximum current of a molex connector is: There are three typical pin sizes: 1.57 mm (0.062 in), 2.13 mm (0.084 in), and 2.36 mm (0.093 in). The 1.57 mm pin can carry 5 A of current, while the 2.36 mm can carry 8.5 A. Because the pins have a large contact surface area and fit tightly, these connectors are typically used for power. What that means is that say for instance you use 3TB seagate 7200rpm drives, which are rated for 2.5A startup current. That 6 way splitter can safely handle 8.5 / 2.5 = 3 hard drives. Add to that, the fact that splitters are not generally considered a commodity item, they are banged off in the millions in a Chinese factory who's quality control on the specifications are poor (ie: they never fit quite as tight as they should), the deciding factor by distributors on what to stock is generally whichever one is cheapest for them to buy.
May 20, 201610 yr Author Thanks again squid. I agree with everything you said. However if my back plane has 12 molex connectors feeding it. Would I be better utilising both molex and Sata cables from the psu?? Thus splitting the load over 4 cables?? Better than just using the satas surely.... Additionally: what is the most robust connector for ampage? Molex or SATA connectors (to anyone that may know!)
May 20, 201610 yr If its a norco 4224, then IIRC you actually only need to connect one molex per backplane. The other is for a redundant power supply. if [its a modular supply, get an extra couple molex cables from the manufacturer (I just emailed antec for my powersupply and they mailed them to me @ n/c) If its not a modular supply (and I'd question the ability of it to run max 24 drives given how little accessory power they gave you), get a pair of molex to sata power adapters that will leave you only needing one molex splitter
May 21, 201610 yr Which leads me to my next question... PSU's like the Corsair RM750X that have 62.5A on the 12v line only ever terminate to 2 molex connectors.... That sounds worrying... If you look at the spec of 18awg wire (which most splitters seem so be) then the sustained maximum ampage is around 16 amps! so surely powering say my 12 molex connectors on my back plane from 2 molex connectors pulling potentially 48 amps (briefly) Is just asking for trouble?? Can anyone recommend any good splitters for getting around this issue? I know that the length of splitter comes into play and the fact that the power is a brief surge but then numbers dont seem to add up... 12v single rail (62amps!) ---> 2 molex connectors (Carrying all power accross them!) = FIRE?? I was looking at these splitters, which benefit from being short but are still only 18awg... thoughts from people running 24 bay cases? Whose the go to? http://www.moddiy.com/products/Top-Quality-18AWG-Molex-to-3-x-Molex-Cable-Splitter.html The RM750x has 7 molex connectors, not 2. If you need more, you also have 8 sata connectors, then you will need sata to molex adapters, NOT splitters. Example: http://www.newegg.com/Product/Product.aspx?Item=N82E16812706032&cm_re=sata_to_molex-_-12-706-032-_-Product Then you would have 15 molex connectors, if you actually need 16 molex connectors (and they are not just for redundant power supply, which you don't need since you only have 1 psu), you can step up to the RM850x, which has 8 molex connectors, and 10 sata connectors. With 10 sata-molex adapters, you would get a total of 18 molex connectors. I don't know if the sata-molex adapters I liked you are good quality, they where just an example. Get some good quality ones, and not the cheapest one on ebay.
May 23, 201610 yr Author The RM750x has 7 molex connectors, not 2. >> Connectors yes - But all the connectors come off 2 wires from the modular PSU (It's the maximum ampeage of the cables i'm more concerned about tbh. Hence why i proposed it may be a better idea if i were to run 4 cables from the PSU (2 modular cables with molex ends, and 2 modular cables sata ends.) That way i can break the ampage up over 4 runs from the psu. If you need more, you also have 8 sata connectors, then you will need sata to molex adapters, NOT splitters. Example: http://www.newegg.com/Product/Product.aspx?Item=N82E16812706032&cm_re=sata_to_molex-_-12-706-032-_-Product >> Agreed. Adapters are the way forward. Assuming that i only need to use half of the molex's connectors on the back plane (if the other half are indeed for redundant PSU's) then it's going to be a bit annoying to split the load. It means that every molex on the backplane powers 4 drives. If i only have 4 modular cables then it means 2 of the modular cables will be responsible for powering 8 drives each... Is 8 drives pushing it over one modular cable from PSU? Quick maths would dictate that a cold startup that would be 16 amps... i dont think that any modular cables are rated for that sort of ampage are they? internet resources dictate that most psu modular cables are 18awg which equates to a sustained 9 amps on the cable?! Then you would have 15 molex connectors, if you actually need 16 molex connectors (and they are not just for redundant power supply, which you don't need since you only have 1 psu), you can step up to the RM850x, which has 8 molex connectors, and 10 sata connectors. With 10 sata-molex adapters, you would get a total of 18 molex connectors. >> Yup trying to get clarification ont he XC-RM424S to see whether it needs all 12 powered or not.
May 23, 201610 yr If you need more, you also have 8 sata connectors, then you will need sata to molex adapters, NOT splitters. Example: http://www.newegg.com/Product/Product.aspx?Item=N82E16812706032&cm_re=sata_to_molex-_-12-706-032-_-Product >> Agreed. Adapters are the way forward. Assuming that i only need to use half of the molex's connectors on the back plane (if the other half are indeed for redundant PSU's) then it's going to be a bit annoying to split the load. It means that every molex on the backplane powers 4 drives. If i only have 4 modular cables then it means 2 of the modular cables will be responsible for powering 8 drives each... Is 8 drives pushing it over one modular cable from PSU? Quick maths would dictate that a cold startup that would be 16 amps... i dont think that any modular cables are rated for that sort of ampage are they? internet resources dictate that most psu modular cables are 18awg which equates to a sustained 9 amps on the cable?! 18awg is 16amps with a temperature of 60 °C, and 10 amps at 75 °C (wikipedia: https://en.wikipedia.org/wiki/American_wire_gauge ) The Seagate Desktop HDD 8TB hard drive uses 9w, which is 9w/12v=0,75Amps. Then you could power 16A/0,75A=21 drives on 60°C, and 10A/0,75A= 13 drives on 75 °C.
May 23, 201610 yr The Seagate Desktop HDD 8TB hard drive uses 9w, which is 9w/12v=0,75Amps. Then you could power 16A/0,75A=21 drives on 60°C, and 10A/0,75A= 13 drives on 75 °C. Startup power on that drive is 2A on the 12V line (24W). 0.75A is average power after its up and running. And thats a huge difference because of the way unRaid operates, ALL drives can (and do) spin up simultaneously at any point in time, and the wiring / ps has to be able to handle that safely.
May 23, 201610 yr The Seagate Desktop HDD 8TB hard drive uses 9w, which is 9w/12v=0,75Amps. Then you could power 16A/0,75A=21 drives on 60°C, and 10A/0,75A= 13 drives on 75 °C. Startup power on that drive is 2A on the 12V line (24W). 0.75A is average power after its up and running. And thats a huge difference because of the way unRaid operates, ALL drives can (and do) spin up simultaneously at any point in time, and the wiring / ps has to be able to handle that safely. No, you base it of the average power/maximum power by a drive, not the startup power. The startup power is only important for how much the 12v rail can deliver.
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