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Title: RX580 and riser board, PSU with pcie pigtail, wire 16 vs 18 awg? Post by: dcjim1 on January 03, 2018, 12:38:11 AM Hi folks,
Putting together a 6 gpu rig that hopefully run 24/7.... I'm wondering if I need to replace the PSU's #18 AWG pcie 8pin + 8pin pigtail, to 16 AWG ones? Would it make a big difference? I will be using the same cable with PCIE 8pin on the gpu and the pigtail with extension cable will go into the 6pin on its riser board. The pcie cables that came with the psu are 18 awg. Title: Re: RX580 and riser board, PSU with pcie pigtail, wire 16 vs 18 awg? Post by: Undefined31415 on January 03, 2018, 02:03:00 AM Hi folks, Putting together a 6 gpu rig that hopefully run 24/7.... I'm wondering if I need to replace the PSU's #18 AWG pcie 8pin + 8pin pigtail, to 16 AWG ones? Would it make a big difference? I will be using the same cable with PCIE 8pin on the gpu and the pigtail with extension cable will go into the 6pin on its riser board. The pcie cables that came with the psu are 18 awg. The default PSU connectors should be fine for that purpose, assuming nothing is defective. A quality cable *should* be able to handle both 8-pin connectors under load, and the 8-pin + 6-pin configuration that you described substantially less than that. Title: Re: RX580 and riser board, PSU with pcie pigtail, wire 16 vs 18 awg? Post by: dcjim1 on January 03, 2018, 08:47:18 AM Hi folks, Putting together a 6 gpu rig that hopefully run 24/7.... I'm wondering if I need to replace the PSU's #18 AWG pcie 8pin + 8pin pigtail, to 16 AWG ones? Would it make a big difference? I will be using the same cable with PCIE 8pin on the gpu and the pigtail with extension cable will go into the 6pin on its riser board. The pcie cables that came with the psu are 18 awg. The default PSU connectors should be fine for that purpose, assuming nothing is defective. A quality cable *should* be able to handle both 8-pin connectors under load, and the 8-pin + 6-pin configuration that you described substantially less than that. According to a blog post I found @ http://cryptomining-blog.com/tag/pcie-risers/ 18 AWG cables are rated up to 8A, @12V, thats 96W PCIE 8pin with 8pin pigtail should have 3 (?) of those on the pigtail so it comes up to 96W x 3 = 288W max Not sure at what % utilization is best, factoring in some loss along the cable, and assuming RX580 graphics cards will take about 100-150W to cryptomine... Thats about 52% utilization @150W per graphics card....? How much rise in temperature should I expect when the cards run 24/7 ? there's a formula somewhere to calculate all this, I suppose? Title: Re: RX580 and riser board, PSU with pcie pigtail, wire 16 vs 18 awg? Post by: Makak4R on January 03, 2018, 09:02:33 AM Well, those AWG18 are working good and are feeding some GTX 1080ti and not showing any sign of burning or warming
so I'm sure you will pretty ok with this cables with your RX580. if they are really AWG18 and not something different in fact so if your rig is working goo, do not touch and let it be working ::) Title: Re: RX580 and riser board, PSU with pcie pigtail, wire 16 vs 18 awg? Post by: Undefined31415 on January 03, 2018, 09:12:09 AM Hi folks, Putting together a 6 gpu rig that hopefully run 24/7.... I'm wondering if I need to replace the PSU's #18 AWG pcie 8pin + 8pin pigtail, to 16 AWG ones? Would it make a big difference? I will be using the same cable with PCIE 8pin on the gpu and the pigtail with extension cable will go into the 6pin on its riser board. The pcie cables that came with the psu are 18 awg. The default PSU connectors should be fine for that purpose, assuming nothing is defective. A quality cable *should* be able to handle both 8-pin connectors under load, and the 8-pin + 6-pin configuration that you described substantially less than that. According to a blog post I found @ http://cryptomining-blog.com/tag/pcie-risers/ 18 AWG cables are rated up to 8A, @12V, thats 96W PCIE 8pin with 8pin pigtail should have 3 (?) of those on the pigtail so it comes up to 96W x 3 = 288W max Not sure at what % utilization is best, factoring in some loss along the cable, and assuming RX580 graphics cards will take about 100-150W to cryptomine... Thats about 52% utilization @150W per graphics card....? How much rise in temperature should I expect when the cards run 24/7 ? there's a formula somewhere to calculate all this, I suppose? Actually calculating it out is a matter of knowing some principles and formulas of the underlying physics. Unfortunately, using formulas to yield precise predictions would require you to make a lot of assumptions about the system. For example: How is power distributed across the various connections that a card may draw from? (Between the PCIe slot and the onboard power connector(s)) 18AWG should be fine for an 8-pin connector plus a 6-pin powered riser, barring defects. Title: Re: RX580 and riser board, PSU with pcie pigtail, wire 16 vs 18 awg? Post by: crypto-world on January 03, 2018, 10:16:50 AM Be careful if you buy from China. You can buy for example AWG 18 but the real nominal can be AWG 22 look at the thickness of copper.
AWG 16 is a good for heavy duty cards. |