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Michael Moe

Anyone Beta testing SLI ?

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Hi,

 

Getting 15-22 FPS in EGLL/UK2000V3 with ORBX England in the Carenado makes no headroom for GPU with 2.2. so hopefully 2.3 will improve performance further and maybe 2.4 will introduce SLI ? who knows.

 

Is it to soon to invest in another GTX780SC ACX from EVGA or is there a BETA team dedicated to this SLI?

 

Thanks

 

Michael 

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LM has already stated that they are looking into it with NVidia but that's as far as it goes. They have not said that it would be included in 2.3.

 

 

Vic

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LM has already stated that they are looking into it with NVidia but that's as far as it goes. They have not said that it would be included in 2.3.

 Vic

Hi Vic,

 

You may recall that we were told to expect SLI in 2.1, but that all changed and LM have seemed somewhat guarded with their responses on the subject since. Does make me wonder whether NVIDIA are dragging their feet for some reason. I do hope I am wrong.

 

Mike

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Hi Vic,

 

You may recall that we were told to expect SLI in 2.1, but that all changed and LM have seemed somewhat guarded with their responses on the subject since. Does make me wonder whether NVIDIA are dragging their feet for some reason. I do hope I am wrong.

 

Mike

From what I recall Mike,  Beau stated that they are waiting for Nvidia to develop an SLI profile for P3D, so that part is in their lap. What's being done to the code to prepare for that is a question.

 

Vic

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What's odd about the SLI thing to me is that so frequently P3D isn't even fully utilizing the single GPU's we are all using as it is.

 

Why add another gpu until the utilization of what's already there is better?

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Been using SLI with FSX and now P3D V2.2 for a couple of months on a dual 660 OC. Where it comes in handy is IMO multiple monitors. The way NVI sees it, both GPUs are running flat out powering 3 Monitors using Surround (2 connected to the first, 1 to the other 660, VC fullscreen over all 3). I cant complain about performance, it seems to work out fine. The driver is obviously taking whatever is thrown at it and distributes it rather evenly.

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Been using SLI with FSX and now P3D V2.2 for a couple of months on a dual 660 OC. Where it comes in handy is IMO multiple monitors. The way NVI sees it, both GPUs are running flat out powering 3 Monitors using Surround (2 connected to the first, 1 to the other 660, VC fullscreen over all 3). I cant complain about performance, it seems to work out fine. The driver is obviously taking whatever is thrown at it and distributes it rather evenly.

 

Interesting....So perhaps not so much about single monitor users (like myself), but more for the multiple crowd?  That makes sense.  Hope they can ultimately bring some benefits to all use cases.

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Interesting discussion. I'm about to sli my 670 ftw, that should give me plenty of power for p3d 2's 'worst case scenarios'. Well, theoretically at least.

 

This fellow posted this video:

 

 

But, looks like he's misinformed that SLI doesn't work in P3D2. Yet. So it's a confusing video without any proof that SLI actually works.

 

What does LM or NV have to do to make it work? or maybe LM rather meant P3D2 is not 'optimized for SLI', whereas SLI does work, but not optimized, namely, in a way that doesn't yield significantly more fps. As a side-note, LM should be smart enough to finally fix glass avionics rendering, so it doesn't kill fps like it's still doing now.

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We really need some non-sli v sli results in identical flight scenarios.

 

Building an sli system and saying it works fine is not much help here.

 

gb.

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I ran a series of tests on my rig with SLI on/off and without being highly technical, because I am not, there is very definitely a performance boost using the hack that LM provided for using SLI. Sliders 20/30% higher and reduced stutters but not eliminated.

 

Simply switching SLI on and off without the hack has virtually no performance effect on my machine.

 

Mac.

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"we really need..."

 

Well, not really. At present P3D isnt really making use of SLI, and I seriously doubt it has any benefit when using a single monitor. Nvidia GPU all are multicore anyway, adding even more plus the overhead for the bus to power a single output seems, well, strange.

 

I only use SLI because a second 660 was way cheaper than a Titan, so why the heck not. P3D is definitely using both GPUs fairly evenly, at least that is what NVI is telling me.

 

So my advice is, don't bother and especially don't throw any money the SLI way until the use and benefit are proven facts (and are backed by the manufacturers)

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Well, not really. At present P3D isnt really making use of SLI, and I seriously doubt it has any benefit when using a single monitor. Nvidia GPU all are multicore anyway, adding even more plus the overhead for the bus to power a single output seems, well, strange.

 

I only use SLI because a second 660 was way cheaper than a Titan, so why the heck not. P3D is definitely using both GPUs fairly evenly, at least that is what NVI is telling me.

 

So my advice is, don't bother and especially don't throw any money the SLI way until the use and benefit are proven facts (and are backed by the manufacturers)

 

 

I agree - same thing goes for g-sync also

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"we really need..."

 

Well, not really. At present P3D isnt really making use of SLI, and I seriously doubt it has any benefit when using a single monitor. Nvidia GPU all are multicore anyway, adding even more plus the overhead for the bus to power a single output seems, well, strange.

 

I only use SLI because a second 660 was way cheaper than a Titan, so why the heck not. P3D is definitely using both GPUs fairly evenly, at least that is what NVI is telling me.

 

So my advice is, don't bother and especially don't throw any money the SLI way until the use and benefit are proven facts (and are backed by the manufacturers)

 

 

I did not say we we need SLI period but to we need see if

there is any advantage at the moment by On/Off testing.

What's the point of theorising when you can run a simple test to find out.

How about doing an On/Off test run and see what you get.

 

gb.

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I did not say we we need SLI period but to we need see if

there is any advantage at the moment by On/Off testing.

What's the point of theorising when you can run a simple test to find out.

How about doing an On/Off test run and see what you get.

 

gb.

 

I thought that was obvious. If you read the SLI threads, you will notice, that most of us who use it find it hard to quantify the effect of SLI. So it is IMO safe to say that it is marginal at best, especially in single monitor config. There certainly is no "wow" effect and no magic silver bullet in SLI at present, even after tweaking your heart out. This may change in the future, but as of now my statement stands, made by reading the forums and the observation of my own system.

 

SLI helps (me) when running a spanned VC full resolution view on multiple monitors. I got about 20% more frames in FSX+DX10. I just assume it is the same with my new P3D setup, but I never bothered to check. In a tweaked and multi monitor environment this is not a "simple on/off" test. I  would have to reroute my monitors, pull one GPU to make sure the driver does not interfere, maybe even do a clean reinstall (of the driver) and again set up Surround. Then I get the challenge that I had my NVI profile tweaked, so I would have to do this again for single GPU. No need to tell you how time consuming this tweaking business is.

 

My best guess is, that a single 780ti would do better in all respects. But that test has to wait for now.

 

Best

nuit

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With all of that said, SLI will eventually be beneficial, and therefore it's worth the investment imo. Also consider SLI is already beneficial in many other titles.

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With all of that said, SLI will eventually be beneficial, and therefore it's worth the investment imo. Also consider SLI is already beneficial in many other titles.

 True. But then again, it might not. Wouldn't be the first time a technology is intruduced that fails to fulfill its promises.

 

Would you like some conspiracy theory on why SLI is stalling a bit? What is in the best interest for NVIDIA, selling the single "big iron" or multiple "lesser" GPUs? If two 660s would have the same performance as a single 780 while at the same time being a lot cheaper, methinks not so many people owning the older cards would willingly swap for the latest and greatest. Just my 2cent.

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SLI is not new. It delivers amazing results in other titles. SLI stalling? what do you mean? and no, a lot of people still prefer single gpu, but Nvidia is doing pretty good with it's SLI drivers. I honestly think that a single gpu will never cut it, that's also how the market is planned. It's also better (imo) to get two separate cards than buying a dual gpu card, like Titan Z or upgrading every gen.

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Hi adi,

 

also true.

 

I just doubt the ability of the PCIe plus SLI bus to run the necessary synchronisation protocol nearly as efficient than a dual GPU on a single card could. Not to mention that your software still has to make use of this or it doesn't have any effect at all.

 

While I'm at it, @ll please be advised that for running SLI one needs the right motherboard. In my case I haven't got the right one, so instead of running two GPU on 3.0x16 PCIe, by using SLI it gets bogged down to x8 for both.

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Worry not, 98% of the motherboards offer SLI support @ 8x/8x. The difference from both running @ 16x vs 8x, is negligible.

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Why does it seem that many who say "SLI is useless and we don't need it", isn't running SLI?  

 

My results

My Rig

Core i7 2600k @ 4.5ghz on water

8GB DDR3-1600

Asus P8Z77-V

2 Samsung 840 250GB Raid 1

(2) GTX 780ti Classifieds - latest 337 drivers

120Hz LED Monitor

 

I tried the AFR-2 setting in the NI Control Panel along with adaptive V-Sync

Running in SLI had a HUGE  decrease in framerate, I am talking 50% loss!

 

I do mostly bush flying in the Carenado C185 Tundra.  I can take off out of CBB7 (Orbx PNW) and easily see 120+ framerate on a single card.  If I load up the same flight on SLI, I am lucky to break 60 fps!  This difference isn't quite as bad in populated areas, but still unacceptable IMO.

 

I can run many other titles Single vs SLI and see a huge difference.  Warthunder, ARMA 3, and Battlefield 4 are some examples.  Heck, ARMA 3 is still CPU bound just like P3D and I would say as far is simulation is concerned, right on par with P3D as well.  

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What's the word on SLI support for 2.3? Was it included? Any updated results from testing in 2.3?

 

Thank you!

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No it was not included. Still waiting for NVidia to create a profile. Works about the same as in 2.2.

 

Vic

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No it was not included. Still waiting for NVidia to create a profile. Works about the same as in 2.2.

 

Vic

 

Thanks Vic, appreciated.

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SLI is not doing much for me ... IMHO, SLI support is going to be paramount to the success of the platform moving forward ... they'll need that before they move onto 64bit ... LM know that, hence why they are working with nVidia and have been "hoping" to get it working since v2.1.  But it's clearly a 2 party process and LM can't do it alone ... they need nVidia support.

 

AFRFriendly approach is the only time I saw improvements with SLI ... any other attempts using the standard Prepar3D.exe resulted in lower performance.

 

However, for multiple displays you can drive each display using individual video cards so no drastic reduction in performance ... if SLI doesn't come about, this is probably where my 3-way SLI Titan Black setup is going (drive 3 4K monitors).

 

But, I keep hoping LM/nVidia can sort this out ... it was VERY unfortunate that nVidia broke P3D V2.x compatibility with their latest WHQL drivers and it certainly does bring into question what is exactly is going on between LM and nVidia.  However, I keep hoping ... being negative about it isn't going to help.

 

Cheers, Rob.

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You're right, this is paramount.  I recently stepped up to two new cards in anticipation of SLI support for both P3D and Digital Combat Simulator, and now I'm biding my time, waiting for my expenses to be worth it.   SLI is a big deal.

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