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Other => CPU/GPU Bitcoin mining hardware => Topic started by: BkkCoins on June 26, 2011, 01:06:21 PM



Title: PCI - PCIe x16 Adapters and 5770s
Post by: BkkCoins on June 26, 2011, 01:06:21 PM
I saw someone mentioning here using PCI -> PCIe adapter (with cable I presume but don't know).

Does this type of thing actually work? I have a Mobo that has 1 x PCIe x16, 2 x PCI, 1 x PCIe x1.
If i can wrangle two more ATI 5770s into this I'd go for it.

What is the downside if it does work? I'm not ever going to use for gaming just mining under Linux.

Thanks for anyone who can set me straight as GPU cards are something I never usually deal with.


Title: Re: PCI - PCIe x16 Adapters and 5770s
Post by: jgraham on June 26, 2011, 01:20:49 PM
I saw someone mentioning here using PCI -> PCIe adapter (with cable I presume but don't know).

Does this type of thing actually work? I have a Mobo that has 1 x PCIe x16, 2 x PCI, 1 x PCIe x1.
If i can wrangle two more ATI 5770s into this I'd go for it.

What is the downside if it does work? I'm not ever going to use for gaming just mining under Linux.

Thanks for anyone who can set me straight as GPU cards are something I never usually deal with.

I've seen these things.  They are PCI -> PCIe 1x adapters.  Regardless of the form factor of the upper PCIe slot.  66Mhz 32bit PCI just barely meets Gen 1 PCIe 1x signaling rates.

Anyway so I can't tell you if it will work...but I can tell you if your card won't work in a 1x slot (or doesn't work well enough) then it won't work with this adapter.  That said PCIe is supposed to scale back depending on the slot you put a card in (and my guess is that mining doesn't require much in the way of bus speed) but you should at least check before spending your $40.


Title: Re: PCI - PCIe x16 Adapters and 5770s
Post by: padrino on June 26, 2011, 01:23:44 PM
It will work good, just make sure you get one with external power (4 pin molex) since the card will tend to expect the 75W out of the slot you can get with PCIe.


Title: Re: PCI - PCIe x16 Adapters and 5770s
Post by: BkkCoins on June 26, 2011, 03:55:12 PM
Thank you for the confirmation.

Since a $40 cable costs almost as much as a low end main board I decided it's better to just get another board that has 2 PCIe x1 instead of older PCI. Easier to deal with. Also given the extra cost for beefier power supply I figure it may be better to stick with 2 GPU/board anyway. Just add another later if I really want.


Title: Re: PCI - PCIe x16 Adapters and 5770s
Post by: Jack of Diamonds on June 26, 2011, 04:32:35 PM
It will work good, just make sure you get one with external power (4 pin molex) since the card will tend to expect the 75W out of the slot you can get with PCIe.

Cablesaurus' brand new PCI->PCI-e adapter comes without a Molex. It's just an extension board you install in a PCI slot.

Maybe you are thinking about the PCI-e x1 to PCI-e x16 adapters.

Quote from: BkkCoins
I decided it's better to just get another board that has 2 PCIe x1 instead of older PCI

You can't use PCI-e x16 cards in normal PCI-e x1 slots without buying extender cables/adapters.
Unless you want to break the slots by sawing off the ends in which case the board loses it's warranty and resale value.


Title: Re: PCI - PCIe x16 Adapters and 5770s
Post by: teknohog on June 27, 2011, 10:15:04 PM
It will work good, just make sure you get one with external power (4 pin molex) since the card will tend to expect the 75W out of the slot you can get with PCIe.

I've been using one without a Molex for several months. The card is a HD5870. Of course, most of the power is coming from PCIe power connectors.


Title: Re: PCI - PCIe x16 Adapters and 5770s
Post by: dalamchops on June 28, 2011, 12:53:31 AM
It will work good, just make sure you get one with external power (4 pin molex) since the card will tend to expect the 75W out of the slot you can get with PCIe.

I've been using one without a Molex for several months. The card is a HD5870. Of course, most of the power is coming from PCIe power connectors.

i think you only need the molex version with 5970 and 6990


Title: Re: PCI - PCIe x16 Adapters and 5770s
Post by: bunnybare on June 28, 2011, 01:00:46 AM
It will work good, just make sure you get one with external power (4 pin molex) since the card will tend to expect the 75W out of the slot you can get with PCIe.

I've been using one without a Molex for several months. The card is a HD5870. Of course, most of the power is coming from PCIe power connectors.

i think you only need the molex version with 5970 and 6990

Is that because of the 2 cores in them?


Title: Re: PCI - PCIe x16 Adapters and 5770s
Post by: Jack of Diamonds on June 28, 2011, 01:27:48 AM
Yes. Though they are a single card, they draw power worth 2 cards (in the case of 6990, 450+ watts if overclocked) because they have 2 cores.

If you use extenders to run 5970 or 6990 it's safer to use extra Molex power adapters injected in the cable ribbon.