Computer Hope

Hardware => Hardware => Topic started by: kfir1980 on January 01, 2017, 12:39:11 PM

Title: use two graphics cards
Post by: kfir1980 on January 01, 2017, 12:39:11 PM
(Sorry for my English. It is not my native language)

I have a video card built on the motherboard (Intel4600). Yesterday I bought a new video card (Rx460). I want to continue using my Intel4600 v.card. in other words, is there a possibility to choice in BIOS which video card  I want to use each time that i turn on the computer?
Title: Re: use two graphics cards
Post by: patio on January 01, 2017, 12:50:10 PM
That would depend entirely on the PC...
Some have options to switch at bootup...in BIOS...many do not.
If it does not show that option  in BIOS you would have to remove the card to use onboard...and vice-versa...
Title: Re: use two graphics cards
Post by: kfir1980 on January 01, 2017, 01:16:05 PM
That would depend entirely on the PC...
Some have options to switch at bootup...in BIOS...many do not.
If it does not show that option  in BIOS you would have to remove the card to use onboard...and vice-versa...

  my Motherboard is Asus H81M-A. you know if it's possible in this Motherboard?
Title: Re: use two graphics cards
Post by: DaveLembke on January 01, 2017, 08:03:26 PM
 Im thinking any video card in the PCI Express 16x slot will disable the integrated. If you go to display properties and dont see a display as 1 and another as 2 grayed out, then the onboard is disabled with the video card installed. If you see a display with 2 then you might be able to enable it.

That motherboard has 2 qty PCI Express 1x slots. While 1x slots are horrible for gaming if you need it just for web surfing for the extra display then it might be a solution, however you can run into a nightmare with competing video cards and mixed video drivers and they dont give these 1x video cards away they are kind of pricey for video cards that are not really for gaming due to the choked off bandwidth of a 1x slot.

What connection types are you looking for ( VGA, DVI, HDMI ) and are both to be used for gaming or just 1 of them? Does the 2nd display support any of the unused connection types on the Rx460 video card to where it might be just that you need a HDMI cable to get the video card to drive 2 displays vs relying on another GPU ?

Title: Re: use two graphics cards
Post by: Salmon Trout on January 02, 2017, 05:03:31 AM
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Title: Re: use two graphics cards
Post by: kfir1980 on January 02, 2017, 06:42:37 AM

What connection types are you looking for ( VGA, DVI, HDMI )

vga

 and are both to be used for gaming or just 1 of them?

only rx460 for gaming

 Does the 2nd display support any of the unused connection types on the Rx460 video card to where it might be just that you need a HDMI cable to get the video card to drive 2 displays vs relying on another GPU ?

I only have one screen. I use windows 7 and tails os 2.91. tails Does not support the gpu of amd (rx460). But tails supports the Intel GPU (intel4600). I need the intel4600 just for tails.
Title: Re: use two graphics cards
Post by: patio on January 02, 2017, 06:53:57 AM
The issue is tails...i wouldn't swap cards just to run that...
But thats just me...
Title: Re: use two graphics cards
Post by: DaveLembke on January 02, 2017, 08:46:59 AM
Quote
The issue is tails...i wouldn't swap cards just to run that...
But thats just me...

Id find a cheap or free computer to run Tails on and not swap back and forth between adding and removing the video card. Each time the card is removed and installed it has the risk of damaging the video card or motherboard. Cards are intended to be stuffed into slots and left alone.
Title: Re: use two graphics cards
Post by: patio on January 02, 2017, 08:54:57 AM
Couldn't have stated it better...
Tails needs a lotta work from what i've seen...and there are more efficient ways to do what i think he wants to do...
Title: Re: use two graphics cards
Post by: kfir1980 on January 02, 2017, 09:28:18 AM
Id find a cheap or free computer to run Tails on and not swap back and forth between adding and removing the video card. Each time the card is removed and installed it has the risk of damaging the video card or motherboard. Cards are intended to be stuffed into slots and left alone.

If i can't switch between 2 video cards in my bios. There is another way to do it? Maybe software that do this? Maybe some advanced tool? Maybe somehow add this possibility to my bios? or Maybe replace the bios (if it's possible)? Or anything you can think of?
Title: Re: use two graphics cards
Post by: patio on January 02, 2017, 09:45:04 AM
No...if it's not a BIOS option at this time you are stuck with pullin the card each time including the drawbacks to that approach that Dave mentioned above...
I'd look for alternatives to that app if it were me...
Title: Re: use two graphics cards
Post by: DaveLembke on January 02, 2017, 10:35:52 AM
Quote
If i can't switch between 2 video cards in my bios. There is another way to do it? Maybe software that do this? Maybe some advanced tool? Maybe somehow add this possibility to my bios? or Maybe replace the bios (if it's possible)? Or anything you can think of?

If one was extremely determined and had an electronics background, they could sever specific traces to the PCIE 16x slot to make it optional at boot. Or a custom 90 degree PCIE 16x riser board engineered up that would allow for this. But the problem is that its going through extreme effort to get this to work, and for most its way far and beyond the time and money to make this a reality. I work as an electronics technician for example and I have done hardware modding of electronics, but to me I would go the easier route in running it on a different box vs wasting time and money to alter the way that your computer handles the video card.

 As far as severing devices without having to physically remove devices, I made up a breadboard with two USB ports once and a relay that ran off of the 5VDC. This allowed via a toggle switch selection of using one bootable USB stick over another. The USB sticks were inside of a server that was locked that ran an altered Live Linux OS configuration. The toggle switch mod to swap between USB sticks was added so that a power user at the site could enter the server room, shut down the server. Flip the toggle switch and boot the server. The server would then run off of the other Live Linux OS off the other healthy USB stick. For most people if a USB stick got corrupt, just pop it out and pop in the other. But we needed strict controls on all external USB ports disabled to avoid unauthorized USB sticks, and this board I made internally to flip 4 pins from one USB stick to another prior to boot was the solution and had very little power draw to pull off. Now with this I was only dealing with switching over 4 pins to pull this off. For you to pull off enabling and disabling a PCIE 16x slot you would need to sever a good majority of the pins starting to the PCIE 16x power pins, then data and address line pins if a card in the slot that is not powered pulls down the bus since a video card not powered may inadvertently become a load on the bus since its no longer powered. I have never tried such a mod. It could be done if all the right pins/traces are severed prior to boot or reconnected prior to boot. But its a large project and if it were me, id just grab another computer to run tails on.

So to answer if it could be done... answer is YES, But only with a serious PCI Express 16x slot mod by a professional who knows their way around electronics and wants to buy lots of costly relays as the safest passive method of disconnecting and connecting the PCIE 16x connections between the motherboard and the video card. Relays can get costly with a DPDT 5 Volt or 12Volt relay in the $2.50 range each, and a DPDT relay can only sever 2 pins, so for my project I had 2 DPDT ( Double Pole - Double Throw ) Relays to swap between 2 USB sticks. The issue with lots of relays is that the coil load of all of them on the 5V or 12V or load balanced among both 5 and 12V relays used for switching of enabling or disabling of 2 pins each could load down the PC power supply and overwhelm it, so while I used the 5V from a P-connector inside you might even need a power supply separate from that of the computers power supply to drive this. Additionally one very primitive form of switching would be to add a massive turn type switch that is long and bulky with individual contacts to break and connect the connections between the video card and the PCIE 16x slot mechanically teamed. These switches are very costly.

Here is an idea of how many connections you would need to break and connect to disable and enable the video card in the PCI Express 16x slot. The GND ( Ground ) pins you dont need to worry about and I would keep connected at all times so that the video card is properly grounded and not floating ground at any point to protect it from Static Discharge. I think you can see how wildly overkill a mod of the PCIE 16x slot is to be able to enable and disable the video card.  ;D


[attachment deleted by admin to conserve space]
Title: Re: use two graphics cards
Post by: kfir1980 on January 02, 2017, 03:48:50 PM
If one was extremely determined and had an electronics background, they could sever specific traces to the PCIE 16x slot to make it optional at boot. Or a custom 90 degree PCIE 16x riser board engineered up that would allow for this. But the problem is that its going through extreme effort to get this to work, and for most its way far and beyond the time and money to make this a reality. I work as an electronics technician for example and I have done hardware modding of electronics, but to me I would go the easier route in running it on a different box vs wasting time and money to alter the way that your computer handles the video card.

 As far as severing devices without having to physically remove devices, I made up a breadboard with two USB ports once and a relay that ran off of the 5VDC. This allowed via a toggle switch selection of using one bootable USB stick over another. The USB sticks were inside of a server that was locked that ran an altered Live Linux OS configuration. The toggle switch mod to swap between USB sticks was added so that a power user at the site could enter the server room, shut down the server. Flip the toggle switch and boot the server. The server would then run off of the other Live Linux OS off the other healthy USB stick. For most people if a USB stick got corrupt, just pop it out and pop in the other. But we needed strict controls on all external USB ports disabled to avoid unauthorized USB sticks, and this board I made internally to flip 4 pins from one USB stick to another prior to boot was the solution and had very little power draw to pull off. Now with this I was only dealing with switching over 4 pins to pull this off. For you to pull off enabling and disabling a PCIE 16x slot you would need to sever a good majority of the pins starting to the PCIE 16x power pins, then data and address line pins if a card in the slot that is not powered pulls down the bus since a video card not powered may inadvertently become a load on the bus since its no longer powered. I have never tried such a mod. It could be done if all the right pins/traces are severed prior to boot or reconnected prior to boot. But its a large project and if it were me, id just grab another computer to run tails on.

So to answer if it could be done... answer is YES, But only with a serious PCI Express 16x slot mod by a professional who knows their way around electronics and wants to buy lots of costly relays as the safest passive method of disconnecting and connecting the PCIE 16x connections between the motherboard and the video card. Relays can get costly with a DPDT 5 Volt or 12Volt relay in the $2.50 range each, and a DPDT relay can only sever 2 pins, so for my project I had 2 DPDT ( Double Pole - Double Throw ) Relays to swap between 2 USB sticks. The issue with lots of relays is that the coil load of all of them on the 5V or 12V or load balanced among both 5 and 12V relays used for switching of enabling or disabling of 2 pins each could load down the PC power supply and overwhelm it, so while I used the 5V from a P-connector inside you might even need a power supply separate from that of the computers power supply to drive this. Additionally one very primitive form of switching would be to add a massive turn type switch that is long and bulky with individual contacts to break and connect the connections between the video card and the PCIE 16x slot mechanically teamed. These switches are very costly.

Here is an idea of how many connections you would need to break and connect to disable and enable the video card in the PCI Express 16x slot. The GND ( Ground ) pins you dont need to worry about and I would keep connected at all times so that the video card is properly grounded and not floating ground at any point to protect it from Static Discharge. I think you can see how wildly overkill a mod of the PCIE 16x slot is to be able to enable and disable the video card.  ;D




Thank you very much men. I have knowledge in electronics. I think I'm able to do it :)
Title: Re: use two graphics cards
Post by: DaveLembke on January 02, 2017, 04:05:26 PM
Quote
Thank you very much men. I have knowledge in electronics. I think I'm able to do it

Best of luck and you will want the length of all pin redirects for open/closed state to be as short in length as possible. Too long of a distance between the video card and the slot and you will run into timing problems. Everything happens very very fast and I have heard of other Electronics Techs and Engineers running into issues if the distance between components is increased. Added length of wire for a signal and your adding delay in the signal getting from point A to point B.  :)

With USB adding an extra 6 inches of wire was no problem, but PCIE 16x slot is way more sensitive to timing. If you look at traces on a board and wonder why they seem unusually longer than they should be than others, its sometimes due to having to have timing spot on and adding length to a trace adds a very very small delay to the signal reaching the other end of the circuit. Additionally you will have to worry about electrical noise.

Some riser ideas can be found here and this project is going to be kind of time consuming and parts expensive to pull off:
https://www.amazon.com/Thermaltake-PCI-Express-Shielded-Riser-Extension/dp/B01AXZV2IA/ref=sr_1_1?ie=UTF8&qid=1483399424&sr=8-1&keywords=pci-e+x16+riser+cable

I as an Electronics Technician of 22 years wouldnt do this project. Especially if this computer is your only computer and you cant afford to burn it up if you mess up your mod. Info shared and what you do with it is at your own risk. ComputerHope and myself are not liable for any damages. Had to state that cause this is a wild project if you follow through with it.  ;D
Title: Re: use two graphics cards
Post by: camerongray on January 02, 2017, 04:28:51 PM
I certainly wouldn't attempt that - I'm not an electronics expert or anything but I do have a working knowledge. You're almost certainly just going to end up breaking something.  Tails is just Linux so I can't see why you can't just configure it to run your graphics card correctly and if you genuinely can't then look into using a different distro that does support the card and configure it with all the "privacy" stuff that Tails includes.

If you're still looking for a BIOS option then you would be wanting to look for something along the lines of "Init Display First", "Primary Video Adapter" or similar with options such as "Onboard", "Integrated", "PCI-E", "Auto".etc - You'll just have to flick through various menus to look for it.