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Author Topic: 1500W psu for $133 I assume it fail??  (Read 2721 times)
El Cabron (OP)
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February 06, 2012, 10:08:11 AM
 #1

http://www.computeandmore.com/productlist.php?id=854

This is not really a great PSU I am guessing? If it is just okay, how many 7970s could this support (limit on cables)? Thanks.

Sorry El Cabron, you are banned from posting or sending personal messages on this forum.
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https://bitcointalk.org/index.php?topic=622250.msg7030081#msg7030081
Chefnet
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February 06, 2012, 10:22:51 AM
 #2

if you can manage the 4 rails correctly it is possible to have a max of 6x7970 with best in MH/watt and not MH/s

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February 06, 2012, 10:36:52 AM
 #3

because there are 4 lines for 12v (2 with 20A = 2*240W and 2 with 40A 2*480W) if your cards using under 200watt it is possible to get it worked with 6 ones.

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February 06, 2012, 10:53:53 AM
 #4

:-) you are welcome. most of the psu's haven't enough cables. so for more than mostly 3 and for good psu's 4 cards you need adapters. and normally it is better to choose a psu with one 12v rail for example http://www.super-flower.de/index.php?id=112 it has +12V: 108A = 1296W :-) so it is possible to run on this psu 6*7970 with a preety high load.

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February 06, 2012, 11:02:14 AM
 #5

http://www.computeandmore.com/productlist.php?id=854

This is not really a great PSU I am guessing? If it is just okay, how many 7970s could this support (limit on cables)? Thanks.
I had a walk around Pantip a few months back and came across a bunch of ToughPower PSU at absurd low prices for high wattages. I pretty much assumed these were some Chinese fakes that had hit the mall (as happens sometimes). At that time ComputeAndMore didn't carry them but maybe now they have been pressured (by competition) into selling them.

I bought my Corsair at that shop and they seem to be one of the few shops with good PSUs and reasonable pricing. I wasn't willing to take a chance on the ToughPower 1500 and similar ones. I have no idea what they are but the prices are enough to scare me away. (If I had more time I would have checked their website to see if they even make such a beast and what the normal price would be).

For adding more cards often you need Y cables. Many GPUs come with some Molex to 6/8 pin adapters too. My Sapphire ones did and I just used those.

BTW Also some months back the shop directly across from ComputeAndMore had SuperFlower PSUs for a pretty low price. I almost got one but then decided (from past experience in Pantip) that I'd better just stick with Corsair. That shop also had a few XFX and Sapphire GPU cards on sale too.

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February 06, 2012, 01:35:09 PM
 #6

BKKCoins thanks for the info, withe the Y adapters I was only able to get 1 extra 5850 hooked up with 3x 7970s and a 6970. Still do not understand how I can get the 6th:(

Thx

You have 8 4-pin molex connectors and 12 sata connectors in that 1.5kW toughpower
(in theory), this is enough to power 4 extra GPUs from molex connectors through sth like this (molex to pci-e connectors):





And another 6 extra GPUs from sata to molex + molex to pci-e:



In this example I am assuming each GPU needs 2x6 pin pci-e connectors, there are molex to pci-e connectors which allow connection of two molex cables for stability, you can also find 2x molex to pci-e 8 pin connectors.

Would've forgotten.. even if you can it doesn't mean it is good to run 6 GPUs through sata, additional adapters increase resistance so it might not be very stable.

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February 06, 2012, 01:53:18 PM
 #7

there are also sata to 6 pin pcie cables (if you need some tell it to me)

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February 06, 2012, 02:04:18 PM
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there are also sata to 6 pin pcie cables (if you need some tell it to me)

They quite hard to get, do you ship to Poland? If so, what's the cost per unit with shipping?

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February 06, 2012, 02:12:10 PM
 #9

Also watch out about overloading the rails.

Sadly it will likely take some experimenting.  The concern is if you have one long power cable w/ 3 or 4 Molex or SATA connectors and you adapter all of them then they are all on the same rail. 

Even if you use two different power cables (the SATA/Molex cables which actually plug into the PSU) they could still be on the same rail. 

It likely will take some trial and error to find a good stable config.  Make sure you have some device to measure power draw at the wall and compare it against a good PSU.  If you find a good stable at crappy efficiency = more wasted power = higher mining costs then the "savings" really aren't worth it.

So your best bet is to buy one, try it, test it, and if it works out then buy a lot more and configure them the same way.

On paper it is a decent PSU
http://www.plugloadsolutions.com/psu_reports/THERMALTAKE_TP-1500M%20TP-1500AH5CES_ECOS%202547_1500W_Report.pdf

however in reality I found the 1000W unit to be lacking.   I would get power trips even as low as 780W DC.  I assume it was due to the crappy multi-rail setup resulting in power I couldn't tap.  I tried a lot of different configurations of wiring but I couldn't get it to work.  I ended up RMAing it back to Newegg.

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February 06, 2012, 02:20:41 PM
 #10

there are also sata to 6 pin pcie cables (if you need some tell it to me)

They quite hard to get, do you ship to Poland? If so, what's the cost per unit with shipping?

yes I can ship it everywhere, send me a pm with more details what you want.

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February 06, 2012, 02:42:36 PM
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@ pm'ed both of you.

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February 06, 2012, 09:45:58 PM
 #12

And another 6 extra GPUs from sata to molex + molex to pci-e:

...
Would've forgotten.. even if you can it doesn't mean it is good to run 6 GPUs through sata, additional adapters increase resistance so it might not be very stable.
Wait!
It's not the resistance that worries me, you're going far out of spec with the sata connector.
A sata power connector has three 12V contacts. THe manufacturer's load limit per contact is 1.5 A.
That's just 4.5 Amps for the 12 line resulting in the connector's max load at mediocre 54 Watts.

If (heaven forbid) you try the sata -> molex -> pcie 8-pin combo be sure to have a fire extinguisher at the ready.
The melting connector can short circuit and kill the PSU. If the built-in protections are inadequate, the PSU can kill the whole rig. Definitely not the prudent path to take.
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February 06, 2012, 09:50:39 PM
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It's not the resistance that worries me, you're going far out of spec with the sata connector.
A sata power connector has three 12V contacts. THe manufacturer's load limit per contact is 1.5 A.
That's just 4.5 Amps for the 12 line resulting in the connector's max load at mediocre 54 Watts.

If (heaven forbid) you try the sata -> molex -> pcie 8-pin combo be sure to have a fire extinguisher at the ready.
The melting connector can short circuit and kill the PSU. If the built-in protections are inadequate, the PSU can kill the whole rig. Definitely not the prudent path to take.

That's another thing but 8-pin connectors will always (?) have at least two molex connectors, there are many 6-pin connectors with two molex connectors so it should be enough.
As for the built-in protections only cheap PSUs will take anything along with them at their death.

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February 06, 2012, 10:18:22 PM
Last edit: February 06, 2012, 10:29:29 PM by jake262144
 #14

That's another thing but 8-pin connectors will always (?) have at least two molex connectors, there are many 6-pin connectors with two molex connectors so it should be enough.

To put is simply, the sata connector was designed as a low-current connector.
The issue is, that connector was engineered with ease of insertion/extraction taking precedence over high reliability of the contacts, that's why there are three contacts per each wire.
By design, it is assumed that some contacts will connect cleanly and reliably.

I'm discussing deploying the full 2x sata -> 2x molex -> pcie-8-pin suite of connectors.

If the card actually needs 150 W at the connector, you are overloading each sata connector by 21 watts. Doesn't seem that much but if any of those 3 sata contacts fails to connect cleanly the problem escalates very fast. Some sparking, the connector heats up, possibly to the point of melting, the least of your worries is rig downtime.
Same situation for the 1x sata -> 1x molex -> pcie-6-pin combo.

2x sata -> 2x molex -> pcie-6-pin should be reasonably safe as long as you don't exert pressure on those poor sata connectors.

Treat my post as Public Service Announcement, I'm trying to make sure that pitfalls of developing a cavalier attitude to GPU wiring are on everyone's radar  Smiley

As for the built-in protections only cheap PSUs will take anything along with them at their death.
Still, I why put a rig full of perfectly good 5970 cards at the PSU's mercy?
All hardware will fail, the protection circuit is no exception.
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February 06, 2012, 10:26:04 PM
 #15

Still, I why put a rig full of perfectly good 5970 cards at the PSU's mercy?
All hardware will fail, the protection circuit is no exception.
[/quote]

Like it or not but you are doing it all the time - power supplies have plenty other things to fail at, this is why we all miners buy high-quality PSUs (1kW $50 or 400W for $10 noname / cheap Chinese brand* is not something I use even for non-mining hardware).

*the best and expensive PSUs are also manufactured in China but the quality and price is different : P


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February 06, 2012, 10:31:56 PM
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Like it or not but you are doing it all the time - power supplies have plenty other things to fail at...
Agreed, that's why I always try to minimize the danger by eliminating unnecessary points of failure.
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