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Title: PCIe Power Risers with Capacitors? Are they better then without Caps? Post by: morphers on June 05, 2013, 02:07:01 AM They are Powered Risers with Capacitors and A ground wire. Are these worth it, and would you buy them for a small premium over the standard powered riser? I have seen just a few of these http://i.ebayimg.com/t/NEW-Powered-PCI-E-PCI-Express-PCIe-x16-Extender-Cable-Riser-Card-Bitcoin-Mining-/00/s/MTMyNFgxNjAw/z/c9sAAMXQWlFRpMHp/$(KGrHqEOKpYFGVog!nP,BRpMHpGi9!~~60_57.JPG Title: Re: PCIe Power Risers with Capacitors? Are they better then without Caps? Post by: 3Dfilament on June 05, 2013, 02:21:01 AM Leads for the capacitor are exposed, not good ... a hair floating in the air, or some other thing could bridge it and schwammy! Most run open boxes, so that the cap leads are exposed is not good. It might be effective for OC power spikes for the card attached, but generally, I just think having a Capacitor with exposed leads for generally open box systems is not good. Lots of open boxers are learning that spiders, and baby spiders, etc ... love the warmth of open boxes as they attract insects as well. One invisible thread of spider web, and zappage. I like the concept, but not the implementation.
Title: Re: PCIe Power Risers with Capacitors? Are they better then without Caps? Post by: morphers on June 05, 2013, 02:30:44 AM Leads for the capacitor are exposed, not good ... a hair floating in the air, or some other thing could bridge it and schwammy! Most run open boxes, so that the cap leads are exposed is not good. It might be effective for OC power spikes for the card attached, but generally, I just think having a Capacitor with exposed leads for generally open box systems is not good. Lots of open boxers are learning that spiders, and baby spiders, etc ... love the warmth of open boxes as they attract insects as well. One invisible thread of spider web, and zappage. I like the concept, but not the implementation. You could say that about anything inside a computer, especially any risers because of the contacts and pins that are so close together. Title: Re: PCIe Power Risers with Capacitors? Are they better then without Caps? Post by: EngMan on June 05, 2013, 02:48:36 AM Not sure about the cap, but that could be protected. I do like the multiple power and ground wires. Most powered risers I've seen only have one +12v wire, no ground.
Where did you find them? Price? Thx Title: Re: PCIe Power Risers with Capacitors? Are they better then without Caps? Post by: ReCat on June 05, 2013, 02:50:32 AM PCIe Powered Risers with entire regulated and switching power supplies are better, though. No, not really. What's the point of that? If you need a cap on your rails, then you need to get a better PSU to begin with.
Title: Re: PCIe Power Risers with Capacitors? Are they better then without Caps? Post by: rograz on June 05, 2013, 10:09:51 AM Leads for the capacitor are exposed, not good ... a hair floating in the air, or some other thing could bridge it and schwammy! This is 12V we are talking about and not 40KV power lines ::) Title: Re: PCIe Power Risers with Capacitors? Are they better then without Caps? Post by: p00chie on June 05, 2013, 12:54:23 PM Leads for the capacitor are exposed, not good ... a hair floating in the air, or some other thing could bridge it and schwammy! This is 12V we are talking about and not 40KV power lines ::) yea lol. if a hair floating in the air would cause a shortcut a lot of offices would burn :) just imagine those dust pcs. lol. Title: Re: PCIe Power Risers with Capacitors? Are they better then without Caps? Post by: Hephaestus on June 05, 2013, 01:06:49 PM Not sure about the cap, but that could be protected. I do like the multiple power and ground wires. Most powered risers I've seen only have one +12v wire, no ground. Where did you find them? Price? Thx Most of them don't have extra grounds because you don't actually need them, especially on x16 slots http://en.wikipedia.org/wiki/PCI_Express#Pinout (http://en.wikipedia.org/wiki/PCI_Express#Pinout) Even an x1 slot has 9 ground pins. All the grounds on the card are tied together as well, so you've got 6 or 8 or however many ground wires on your PCIe power connectors. The main reason for powered risers is that most motherboards weren't intended to have six graphics cards on them, and they only have two +12V wires on the ATX connector to supply all the PCIe slots (but 8 grounds). http://en.wikipedia.org/wiki/ATX#Power_supply (http://en.wikipedia.org/wiki/ATX#Power_supply) In my rigs I use three unmodified risers and three where I have the +12V lines completely disconnected from the motherboard and running to a separate power supply. The capacitors are pretty much irrelevant, I would think...graphics cards will already have them. Someone probably just figured they could mark the riser up $3-5 by adding a $0.10 part to it. Title: Re: PCIe Power Risers with Capacitors? Are they better then without Caps? Post by: Grim on June 05, 2013, 05:24:05 PM In my rigs I use three unmodified risers and three where I have the +12V lines completely disconnected from the motherboard and running to a separate power supply. The 3 powered risers are NOT connected to your PSU which is plugged into the motherboard??? Title: Re: PCIe Power Risers with Capacitors? Are they better then without Caps? Post by: Trongersoll on June 05, 2013, 05:47:06 PM i'm thinking that the Cap might be there to cancel any potential RF interference. Back in the day, early 70s, when people were running CB radios with way too much power, people could hear the broadcasters transmissions over their stereo's speakers. the solution was to put a capacitor across the speakers terminals.
Title: Re: PCIe Power Risers with Capacitors? Are they better then without Caps? Post by: Hephaestus on June 05, 2013, 08:27:59 PM In my rigs I use three unmodified risers and three where I have the +12V lines completely disconnected from the motherboard and running to a separate power supply. The 3 powered risers are NOT connected to your PSU which is plugged into the motherboard??? Correct. That's why the lines to the motherboard are severed, unlike this riser which just adds a molex. With this one, you have two parallel paths from +12V to the PCIe connector on the graphics card, so it would have to be the same power supply...putting power supply rails in parallel with each other is...iffy. Title: Re: PCIe Power Risers with Capacitors? Are they better then without Caps? Post by: Eastwind on June 06, 2013, 12:15:50 PM i'm thinking that the Cap might be there to cancel any potential RF interference. Back in the day, early 70s, when people were running CB radios with way too much power, people could hear the broadcasters transmissions over their stereo's speakers. the solution was to put a capacitor across the speakers terminals. RF interference is high frequency. The capacitor shown here is only working for low frequency signal such as below 1kHz. You need to a small capacitor to have lower inductance. I think the capacitor here is not necessary. Title: Re: PCIe Power Risers with Capacitors? Are they better then without Caps? Post by: Eastwind on June 06, 2013, 12:20:58 PM i'm thinking that the Cap might be there to cancel any potential RF interference. Back in the day, early 70s, when people were running CB radios with way too much power, people could hear the broadcasters transmissions over their stereo's speakers. the solution was to put a capacitor across the speakers terminals. RF interference is high frequency. The capacitor shown here is only working for low frequency signal such as below 1kHz. You need to a small capacitor to have lower inductance. I think the capacitor here is not necessary. If you use a signal power supply, it is OK. I measured the output from different rails of a power supply, there is a zero resistance between, that means the output of different rails are connected internally. On the motherboard, it is different. The +12V connector to the CPU circuit is cut (independent) from the rest of the +12V. On the graphics card, the +12V from the PCIE slot is cut (independent) from the 6 pin and/or 8pint connector. |
