WARNING: The techniques below do involve risk, I am not responsible for any mishaps.
ATI (now AMD) and NVIDIA were always the big contenders in the graphics card realm. Generally speaking, NVIDIA brings the most power, but AMD brings in better performance for their price tag. The battle between the two rages on as consumers fight amongst themselves as to who is better and why!
Along the way some new technology came about where you could connect two (or more) graphic cards together. If you connect at least two AMD/ATI graphic cards it's called Crossfire. If you connect two NVIDIA graphic cards it's called SLI (Scalable Link Interface).
Crossfire is now officially CrossfireX. There is some confusion with this name as CrossfireX was normally mentioned in relation to mobile platforms prior to the official change, and at times was also confusingly defined by some as four or more graphic cards in an array. As such, I continue to use Crossfire for just desktop graphic cards of two or more.
SLI and Crossfire offers better performance, mainly for games. It can offer better performance in applications, if those applications take advantage of two GPU's at one time, which seems rare. But one example is Adobe Premiere Pro. It can use SLI when rendering out video. Traditionally, graphic cards would need to be connected by physical "bridges" and had slots for these bridges. As of now, only AMD graphic cards can have bridges without a physical connection.
This is probably the least useful trick of the five I will be discussing. Not because it is boring or difficult to accomplish, but because there is little use for it. Physx is proprietary to NVIDIA and used in some games to help increase aesthetics. (There are also applications that use Physx, but I believe that's even less popular than building games with it.) If you've played any of the newer Batman games on the PC, one difference with enabling Physx on a NVIDIA card would be the smoothness and wrinkling of Batman's cape as he moves about. It is a nice complement for details, but I have never found myself using Physx despite my favoritism for NVIDIA cards.
Anyways, Hybrid Physx is a way to connect an AMD card to a NVIDIA card and increase the performance for Physx games and applications. On older NVIDIA cards and AMD cards, this seems to work quite well. There are mixed results for newer cards, but it can be done. I even read about someone getting a GTX 680 and a R9 290 to work together, which oddly enough, I have.
The titles will have the links for the full instructions, but I will give the essential requirements in order to get them working:
Older NVIDIA Graphic Cards
- First install NVIDIA drivers ranging from version 258 to 285 for the GeForce 256.
- Then download and upgrade the Physx SS driver up to version 9.11.0621.
- Now download and install the Hybrid Physx Mod 1.05ff. This should automatically patch the necessary files to get Hyrbid Phsyx to work.
- Optionally, you can use the command line included to set a desired configuration, which I assume they mean display.
Newer NVIDIA Graphic Cards
- First download and install PreHybrid for older games
- Then download and install either NVIDIA 320.49 drivers for GTX 500 series and below, or NVIDIA 314.22 for GTX 600 & 700 series. These drivers do not include Physx, which is why they are specifically used.
- Download and install the latest AMD Catalyst drivers.
- Download and install Physx driver version 9.13.0725.
- Download and run Hybridiz.
- Delete numerous files in the game directories.
Note: The Hybrid Physx for newer NVIDIA cards will only work on Windows 7/8, and can only work on games that use Physx 2.0 (not 3.0).
For newer cards there seems to be a lot more work involved in getting everything setup. There are multiple files to download and delete, and if you upgrade your NVIDIA drivers (Physx will not upgrade if already present in the system), you will need to rerun Hybridiz. There is also the chance of things crashing if not done in order and accordingly.
Again, I find hybrid Physx rather useless for so much work. Any game with Physx will run happily without it. I have never been so saddened by a game's graphics (that has Physx), and thought to myself, "I need Hyrbid Physx". If anything, I would more likely just buy another identical NVIDIA card to SLI with, and increase the Physx performance that way. But it is a cool experiment to try if you're bored and have some time.
HyperSLI is the ability to enable SLI on motherboards that do not officially support it. Originally, this innovation was brought to the public by Asrock. They had created a patch for their motherboards with a certain chipset. The team at NGO took the patch and modified it to work for any motherboard.
I personally performed this method on an ASUS Crosshair III motherboard. I had bought two NVIDIA 560 Ti's not realizing that the motherboard only supported Crossfire. So I went on a hunt to see if I could enable SLI, and luckily, I could!
The newer versions of this are done by a different team and they call it HyperSLI. It is just as simple (if not simpler) to use, and should be just as successful. The process is quite simple and will take very little time to complete:
- Ensure that your CPU supports virtualization technology.
- Ensure that your BIOS has virtualization enabled.
- Download HyperSLI 1.0.
- Open HyperSLI.
- Push the button to enable SLI.
- Reboot PC.
NVIDIA requires at least two x8 PCI Express slots to officially offer SLI support. Motherboard manufacturers can often save money by offering one slot as a full x16 and another at x4. So, there are still plenty of motherboards out there with just Crossfire support, and if you happen to have one, this will almost certainly work!
Different SLI was actually created by the same team who created HyperSLI. ATI always had the added benefit of being able to Crossfire between other graphics cards (not all, but those that use the same architecture) despite their models. NVIDIA never grasped the concept and forced consumers to buy similar models [meaning same model but with the "choice" of a different manufacturer].
Different SLI has come along to change all that. Different SLI allows you to take two different model NVIDIA cards and put them into SLI. Initially, the theory was that only NVIDIA cards using identical GPU's could successfully perform Different SLI. There were some tests to support this, while there were some that did not. At this point, it has been determined that the hardware ID's have to match, or rather the three specific characters.
This really opens the doors for many NVIDIA users. There are numerous cards that can be SLI'd. If you have a cheap card, you may be able to upgrade with a better card and get SLI. If you have a new card, you may be able to get an older, cheaper one and get SLI. In any case, there is a good chance you can get that additional boost in performance that SLI delivers.
Here are the steps you need to know, including preparation, in order to perform Different SLI:
- Check the first post here for your card and what other cards match it for SLI purposes. Look at your graphic cards first three characters/digits after "DEV_".
- Compare these to the graphics card you wish to try. If they are a match, then they should work together.
- Install the graphic cards into the computer.
- Connect the cards by a SLI bridge. If you do not have a SLI bridge you can buy one from Amazon. But if one of your cards does not have an area for the SLI bridge, you are out-of-luck.
- Download Different SLI 1.0.
- Unzip the folder and start Different SLI.
- Press the "Patch" button.
NOTE: GTX 970's & 980's hardware ID's match, so they should be able to SLI together.
You should fully know if a card you plan to get, or already have, should work with Different SLI before trying this. There is no reason to run out and buy a card that you come to find out simply won't work. Just as there is no reason to try Different SLI on two cards you already own if they are not compatible.
This is by far the most interesting item to discuss (for me). I have been wanting to try this for some time, but have either not had the funds or not had the resources available to try. When I first found out about this method I had a GTX 480. The GTX 580 was incompatible (in either theory), and I already had SLI, so I moved on.
But now I use a GTX 680 and would love to give a GTX 770 or a GTX 690 a try; just to see if I can do it, and how good it can do if so. With a GTX 770, it should react more like a GTX 680 or 770 SLI. However, a GTX 690 would be like a GTX 680 Tri-SLI setup. Others will argue more like a GTX 670 SLI with a 680, despite the amount of CUDA cores is exactly double that of a GTX 680, and a GTX 690 tests near-identical to that of a GTX 680 SLI setup. It would be even more interesting since a GTX 690 can be said to be about on par with a GTX 780 Ti or a GTX 980, depending on the settings and game. I would really like to compare benchmarks between a GTX 680 & 690 SLI versus a GTX 780 Ti SLI or GTX 980 SLI. But I digress...
Hybrid SLI/Hybrid Crossfire
Hybrid SLI or Hybrid Crossfire refers to having a discrete GPU (a GPU not part of the motherboard or the CPU) that can link with the graphics chip integrated into the motherboard or CPU. This is not to be confused with NVIDIA's Optimus or AMD's PowerXpress on mobile chips (laptops and notebooks). These features actually just switch between either the discrete graphics card or integrated graphics depending on the GPU load.
While originally this was used with motherboards that had integrated graphics, this is now largely related to CPU's. With the popularity of CPU's incorporating integrated graphics, there has been less of a need to have motherboards with integrated graphics. I also wanted to briefly mention that AMD refers to their CPU's with integrated graphics as APU's (Accelerated Processing Units). Yet the definition for an APU would actually apply to Intel CPU's as well.
Just for a bit of history, and for my next thought, the idea of combining two graphic cards was and is called hybrid-graphics. However, this is about switching from discrete to integrated graphics, not combining the two.
Intel still has hybrid-graphics, but NVIDIA no longer supports it. You should be able to downgrade your drivers and do some tweaks to get them to work, but you may have a performance impact for newer cards. Intel also has two types of hybrid-graphics: Fixed & Dynamic. Fixed determines which graphics source to use based on power. Dynamic determines which graphics source to use based on GPU load. NVIDIA does still have an official page with Hybrid SLI information here, but you'll notice that it hasn't had an update for newer cards in some time...
AMD offers Radeon Dual Graphics, which can be turned on in the BIOS when using a AMD discrete graphics card. This is considered Hybrid Crossfire and can give an added boost when necessary. This should never be considered a better solution in comparison to a true Crossfire, however.
SLI with Crossfire!
I recently came across a video on YouTube where a group has apparently done the impossible. They have SLI and Crossfire in the same rig! Now, unfortunately, this isn't SLI in use with Crossfire. This is just having both technologies in the same computer, which is still unheard of.
Evidently, you just plug up a monitor to the respective setup and change the primary display to whichever setup you want to use. The price quoted from the video is $5000. Not too bad for a special gaming rig, but too steep for my blood.
A couple things of note: I hate it when people discover new ways to do things and do not share it freely with the public. Yes, making money off an original (working) idea is great, but all of the other techniques I have listed are and always have been free. Then again, I could barely fit three cards in my current rig, so no real loss there.
Another thing is that I have been trying to deduce how they could have done this and I think the most obvious point is Crossfire. After looking at the video, you can tell that the cards are really snug. Crossfire does not need a physical bridge (if you are using a R9 285 or higher), and because of that it has made it all possible. Without that one feature, this video would not exist without some sort of custom bridge connectors.
I imagine that the drivers are where the meat of this method lies. At first I was thinking, maybe the tweaked the drivers to work properly, or maybe they have their own special software running. But I then began thinking about some of my own testing I had done on some AMD R9 290's I bought last year. My desktop was, and is still, using a GTX 680. So, I already had the NVIDIA Control Panel installed. I didn't want to bother uninstalling and reinstalling it (as I wanted to keep using the GTX 680), so I just installed AMD Catalyst alongside it. The only problem that ever occurred was that when the GTX 680 was the only card in my computer, I would get an error message from AMD Catalyst stating no AMD graphic cards were present.
A long time prior to that, I had been trying to SLI two GTX 480's. I was actually trying to setup a Tri-SLI setup, which led me to a lot of random testing. On this motherboard, it was recommended to have a single graphics card in the top (first) PCI Express slot. It was also recommended to use the last (third) PCI Express slot if the first had any issues. I did end up trying the last slot with a single graphics card during one of my trials and was successfully able to use my monitor. I believe I was even able to use the middle (second) slot without issue...
Why are these situations important to know? Well, first off, this means the two sets of opposing drivers can be installed and used without conflict. The second realization is that there can be more than one primary slot for a graphics card. Recall that in the video it is stated to switch from SLI to Crossfire or vice-versa you simply need to select the primary card in the settings for your display. What I then imagine is that having dual displays is actually unnecessary, since only one works at a time. Meaning that you could have one display plugged in one setup, but could then take out the plug and reinsert it into the other setup when wanting to switch. You would then change the primary display card and still have the same effect. Two displays just makes it easier (lazy!).
So, what I'm trying to get at is that I don't think there is really trick involved. As long as you have newer AMD cards that do not rely on physical bridge connections, and a motherboard that supports 4-way SLI/Crossfire, you should be able to accomplish this without any modifications or hacks. Unfortunately, I am currently unable to test this theory. I do have enough graphic cards for Crossfire and SLI, but the motherboards at my disposal will do 3-way SLI/Crossfire at best. There is some sort of legendary add-on board that should allow 4-way, but that item has never surfaced to the public.
This was an enjoyable article to write and share. My hope is that people stumble across it and think, "I didn't know you could do that!" I have a lot of friends that don't even know much of this is even possible, part of that may be that they don't have an investing interest. But I do hope that if you read this you will find the information interesting if not useful.