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Mix and match SLI with ALL Y series GPUs (650m, 750m, 755m) might be possible!

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I am trying to figure out ways to make use of the only ultrabay GPUs that seem to be left on the market, the 650m ones, for people who have later models with the 750m and 755m. To the best of my knowledge, from what some Lenovo techs told me, it seems that the manufacturer they had making the ultrabays went out of business, and that's why we haven't been seeing any 750m or 755m ultrabays for sale. There's no telling if that's completely true, or if that means they'll never produce any more of those for independent sale, however, I think it'd be worthwhile to at least figure out how to make the remaining 650m ultrabays useful for everyone with a Y series Ideapad.

I've been running some experiments with my ultrabay card, and have concluded that for SLI to work, the two cards have to be reporting the same device ID. That is determined at the hardware/firmware level of the GPU. It can't be modified with BIOS, even if you flash a 750m BIOS onto a 650m. However, what's more important for SLI functionality may be at the driver level. If the DRIVERS/operating system can see/report both cards as being the same, SLI should work. More specifically, if you can trick the Nvidia drivers into treating a 650m and a 750m as the same card, it should open up the SLI feature. We know this would work on a hardware level because the two cards use the exact same chip, same number of shaders, memory, etc. The only differences are the clocks, but those can be modified any number of different ways quite easily. SLI will physically work with any of the cards in this laptop series, we just need to get around the device ID/SLI check issue.

So, in my search for a solution I came across this website:

SLI with different cards - techPowerUp! Forums

This guy put together modified driver versions that apparently ignore mismatched device IDs and might allow two same-chip cards to work together in SLI! Most cards that are of the same chip but different names seem to work together with this method. Different chips are hit and miss. I think it would be extremely useful if we could get together and test this out. Unfortunately, I have a 650m system and there are no 750m ultrabays I can use to test this out. However, if someone with a 750/755m system could try it with a 650m ultrabay, we might have what we need!

***I should also note, I've heard of people with the 750m putting 650m ultrabays into their laptop, and saying that the laptop wouldnt allow it to boot up the OS, as if the card were subject to a whitelist. I believe that'd easily be avoided with Svl7's modified/unlocked BIOS. Unfortunately, this means a BIOS mod is required to get this working, but I think that's a small risk to take.

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I feel this will be all for nothing as the Ultrabays will finally be available soon. Unlike all the hearsay and speculation of the past there's actually solid proof now. They are already for sale in other countries, just not in the US/North America yet. Still, good work.

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I feel this will be all for nothing as the Ultrabays will finally be available soon. Unlike all the hearsay and speculation of the past there's actually solid proof now. They are already for sale in other countries, just not in the US/North America yet. Still, good work.

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Contracts do not simply allow a business to go under. If they contracted for a million ultrabays, they would invest time to make sure that corporation doing the work isnt going to just, fall of the face of the earth. Chances are Customs and proper importation and law compliance stalls. We are in North America (atleast I am)...

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Contracts do not simply allow a business to go under. If they contracted for a million ultrabays, they would invest time to make sure that corporation doing the work isnt going to just, fall of the face of the earth. Chances are Customs and proper importation and law compliance stalls. We are in North America (atleast I am)...

What's going on behind the scenes is anybody's guess I suppose. What's for certain is that these ultrabays are currently not available, and haven't been for quite some time. Nobody knows if they're going to liquidate all of their 650m ultrabays, nobody knows if they'll ever start supporting the 14" SLI models again, etc. At least there are alternative means of making use of whatever ultrabays they have available, regardless of the card model inside the laptop,

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SLI with different cards seems awesome, but it's also quite useless considering that you can overclock your 650m and have the equivalent GPU power of a 750m/755m.

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btw this isn't possible. If you put two cards in the same family 6xx then yes, but the faster card downclocks to the slower one. But you can't cross sli 6xx with 7xx. Unless you flashed the 700 to be a 600 series. Which is foolish.

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btw this isn't possible. If you put two cards in the same family 6xx then yes, but the faster card downclocks to the slower one. But you can't cross sli 6xx with 7xx. Unless you flashed the 700 to be a 600 series. Which is foolish.

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I'd have to say you're incorrect. The main point is to use a 650m ultrabay in a 750m system, not vise versa, because that would be utterly pointless. 650m ultrabays are in fair supply, while 750m ultrabays dont exist on the market currently, unless you buy it in a Y510 preconfigured with SLI. With this particular driver I linked, you can SLI two cards of equivalent architecture (shaders, memory, etc.), or in other words, cards that use the exact same chip. This is a system limitation, needing the two cards to be on equal footing so that everything is balanced, otherwise it will crash. A 750m and 650m are the same in every respect except core clocks and voltage, as further evidenced by the fact that I just flashed a 650m to a 750m last week, and it works perfectly fine. However, that does not stop the OS from seeing its true device ID, and determining it's still a 650m. Nvidia restricts SLI to working with two cards of the SAME NAME. To get around that, the modified drivers are set to ignore discrepancies in device ID, allowing the otherwise compatible GPUs to work together in sync. The next common misonception is that core clocks must be the same for SLI to work, but that is completely false. I can run two 650m cards in SLI together at different clock speeds and voltages. They will maintain their individual clock speeds while in use, but the overall performance is limited by the slower card. To get around this issue in the case of two different cards, simply overclock the slower one, since they both have the same speed capacity (because, again, they are the exact same chip).

Give it a read through.

You are 100% correct. I just explained it in layman's terms. It will work if you flash them correctly. However a 650m with a 750m wont work, you would have to flash one or the other.

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Yea, I've been seeing the rumors. But considering how things went down last time they claimed to be selling 750m ultrabays, I wouldn't be overly optimistic. Even if they start releasing 750m and/or 755m ultrabays, I'm pretty sure the 14" models will still get the short end of the stick. To this day, they've never even offered an ultrabay option for the 750m or 755m, and had only a handful of the things for the 650m. Considering it was advertised as being SLI compatible, which it completely is, I think it's worth exploring how to use whatever ultrabay cards are available. This could be a great option in the event that Lenovo just doesn't produce the particular ultrabay version we need, for 14" or 15.6" models. Personally, I find this vexatious fiddling around, trying to find the particular version of the same exact piece of hardware that should be working in all of the Ideapad machines anyway, to be a stupid marketing gimmick by Lenovo well worth ignoring. All they're doing is putting a new spin on the same exact product every time they release a new one. There's really no reason for customers to play this silly supply and demand game they've set up.

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Good news folks! The kind people at notebokreview have improved upon the driver solution for using a 650m ultrabay with a 750m system (or any mix-match SLI system), and it's now available for the latest Nvidia drivers. It has now been CONFIRMED to work!

Mix and match SLI with ALL Y series GPUs (650m, 750m, 755m) might be possible! - Page 5

SLI with different cards - Page 29 - techPowerUp! Forums

Again, you will need to have a modified/unlocked BIOS to get past the whitelist, and it will be helpful to flash a modified BIOS to your 650m ultrabay so you can overclock it to better match the performance of the 750m. Otherwise, a modified BIOS and this driver is all you need to get up and running with SLI without waiting for new ultrabay GPUs to come out!

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The 750m model is available now. Don't make much sense buying it discretely though since the retail price is around 200.

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I just want to confirm if it is possible to get the y400 650 ultrabay and sli it with the y410p 750 since I am guessing that I won't see this near in the near future.

Sent from my iPhone using Tapatalk

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watch this

according to the comments you can get a GPU and ssd on the same ultrabay maybe it is possible

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