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ChrisRay
04-19-05, 11:42 PM
http://www.penstarsys.com/editor/tech/graphics/nvidia/sli_inter/index.html


I think the interview posted on the front page definately needs attention. I m wonderfing by the looks of this interview if Nvidia possibly can support tiling? they say they looked it over. I notice they seem very fond of the AFR method ((Which is no shock since it scales so well))

thoughts? I'll post back later when I have more time.

jAkUp
04-19-05, 11:51 PM
Yes I agree, AFR seems like more the way to go since you don't really have to worry about load balancing. Its the closest we can get nowadays to the old school SLI... Scan Line Interweave :D Where it would draw even and odd lines on the screen. Too bad thats not possible anymore

Raje
04-20-05, 12:12 AM
Sounds like Nvidia SLI will only get better and stronger as time goes on. One thing I was wondering about with ATI's Multi GPU around the corner is if Nvidia had considered ATI's Tiling approach. Obviously they have.

I'm happy to hear that Nvidia has engineers who are dedicated to improving GPU cooling solutions. Hopefully Nvidia cards will have much better cooling solutions in the future. I wouldn't mind paying extra for a good cooling solution (like Zalman's solution).

SH64
04-20-05, 12:39 AM
NVIDIA currently uses symmetric rendering to ensure maximum scaling. In a scenario in which two different GPUs (different pipes and clock speeds) would be used together, the faster card would be ‘dumbed down’ to the slower card’s configuration. While this may sound like a flexible solution, in a typical case this would lead to little to no performance improvement, as compared to the single GPU performance of the faster card.

Interesting.
so the Inq talk about dumping down the clock speeds is correct afterall.

GlowStick
04-20-05, 01:47 AM
Thats gonna be a big no on the super tileing.

But intresting review at least!

Im so tempted to buy a Nforce4 board since my local frys has the SLi modles in stock heh :d

ChrisRay
04-20-05, 01:54 AM
The one thing that concerns me. Is in my experience there is driver overhead in SFR mode. However the CPU overhead seems to have drastically improved from the late 6x.xx to the early 7x.xx drivers. So I dont agree with the statement that driver overhead is non existent.

JoshMST
04-20-05, 08:17 AM
I agree Chris, when we look at SLI performance at lower resolutions, the framerates just aren't competitive with other single card solutions. Only when higher res and AA/AF are added does the SLI solution come out on top.

saturnotaku
04-20-05, 08:21 AM
Only when higher res and AA/AF are added does the SLI solution come out on top.

Isn't that why people would buy an SLI setup in the first place? It sort of defeats the purpose if you're only playing at 1024x768. ;)

JoshMST
04-20-05, 08:28 AM
Haha, my point is that if there is no driver overhead then why at the lower resolutions does the SLI setup not perform as well as a fast single card?

ChrisRay
04-20-05, 08:59 AM
Haha, my point is that if there is no driver overhead then why at the lower resolutions does the SLI setup not perform as well as a fast single card?


I still think the performance impact is minimal and has certainly improved from late 6x.xx drivers to the early 7x.xx drivers. I mean even AFR has CPU overheard. But its definately improved significantly from my own investigations/observances over the past 3 months with 2 sets of SLI cards I own.. ((6600GTs and 6800GTS.))

saturnotaku
04-20-05, 09:16 AM
I'm amazed with the progress NVIDIA has made on the driver front thus far. Considering the overall "newness" of the technology, they're really working hard to make sure it's compatible with both new and old games alike. When I had my two 6600 GTs, I saw some drastic improvements in Far Cry. There are some spots at 1280x1024, 4x AA/4x AF where they outperform the single 6800 GT in my rig right now. A month or two ago, this was not the case.

thegiz
04-20-05, 04:36 PM
. Hopefully Nvidia cards will have much better cooling solutions in the future. I wouldn't mind paying extra for a good cooling solution (like Zalman's solution).

I agree. The cooling solution is abysmal. It's poor by design (for SLI). I've had both the MSI and DFI boards and with that limited spacing, there is only one solution to keep cool, that is water. I've added two Zalman's to my bfg 6800gts and it BARELY fit on both motherboards. I had to use a spacer in between the cards just so the top fan didn't rub on the bottom brace!

The nVidia fan solution by default pulls air from the back of the card (case) over the fround of the card... The opposite of the Arctic DHES solution, and the opposite of most case airflows.

FraGTastiK
04-20-05, 05:05 PM
that part about final polish to SLI Quad Driver,is it Two Dual GPU cards in SLI mode?

I cant wait to have a pair of those with fastest nVIDIA gpu on them.

I dont mind the heat or power consumption,those cards if available deserve the best cooling+power solution around.

Treason
04-20-05, 05:57 PM
The related front-page article about nVidia's nForce4 SLI motherboard sales should be noted too. That's 1.5 million nVidia 6600/6800 series video cards sold along with those motherboards. I would think this gives nVidia more incentive to improve and expand their SLI technology.

Meanwhile there is no competition at this point.

GlowStick
04-20-05, 06:50 PM
that part about final polish to SLI Quad Driver,is it Two Dual GPU cards in SLI mode?

I cant wait to have a pair of those with fastest nVIDIA gpu on them.

I dont mind the heat or power consumption,those cards if available deserve the best cooling+power solution around.
It says Quadro not quad, lol.

Anyhoo, the Quadro series of cards are for professonal workstations.

H-street
04-20-05, 07:51 PM
i wonder how much longer before nvidia realizes what 3dfx realized with the v5 6k..

with so much power needed.. they will need to add an external powersource for the video cards...

JoshMST
04-20-05, 11:12 PM
Haha, back when the Voodoo 5 6K was around, 400 watt power supplies were very rare. Now we see 480 watts and above be pretty common for these upper end machines. I hope that will be enough juice for these cards!

H-street
04-21-05, 12:53 AM
but in the future.. power is only going to increase..

it will almost come to the point where the video card requires just as much power as the motherboard/CPU/RAM .. especially considering that is exactly what the video card is turning into..

it only makes sense that eventually the video card will need its own powersupply (or the current power supplies will need quite a bit of boost)..

who knows what the future holds but i won't be suprised if in the next year or 2 you start to see external powersupplies for the video cards..

FraGTastiK
04-21-05, 02:14 AM
It says Quadro not quad, lol.

Anyhoo, the Quadro series of cards are for professonal workstations.


ty for ruining my dream! j/k

I know what a Quadro card is,specially Quadro SLI,Venturi's posts are everwhere;-) no way you can fail seeing one, this is what happens when you think of something too much and look every corner for a bit of news about it.
Had a glance,read that as as quad,got ecxited,posted that message.

btw Im still looking forward to quad GPU SLI,it should be up their sleeves I guess,hope :-)

JoshMST
04-21-05, 11:36 AM
Yes, in the future power will increase, but I don't think we will see the dramatic increase that we have seen from the 200 watt max days (which was only about 7 years ago). I think that machines with 400 to 500 watts will be the status quo for quite some time, and that CPU/Memory/GPU manufacturers know that they have hit a pretty hard wall. It is just not economically viable for every machine out there to have a 600 watt power supply, and so the chip guys are designing their products now to not go over the 500 watt mark (on a regular basis that is). AMD's dual core chip at 2.2 GHz pulls the same amount of power as their single core FX-55. Intel's Smithfield also pulls less power per core than a Prescott. The GPU guys are also doing a lot to keep power down as much as possible, and this is throug the use of more pipelines without the focus on clockspeed, and with process shrinks and power saving features even on desktop products.

So, I really do not expect a three fold jump in the next 7 years as we have seen in the past. I think that the sweet spot for some time to come will be 480 watts, and only the really high end machines will have 520 watts or more. People and companies simply cannot afford keeping a 600 watt power supply running all the time!

Remi
04-22-05, 10:01 AM
I agree Chris, when we look at SLI performance at lower resolutions, the framerates just aren't competitive with other single card solutions. Only when higher res and AA/AF are added does the SLI solution come out on top.
Don't forget that the more fps you'll have, the more synchronization points (and therefore sync. overhead) you'll get. If you read the patents related to SFR, the solution is actually very elegant and the software overhead is really minimal. It looks like it's the communication between the cards which slows it down, and that's kind of unavoidable right now (I can't speak for the future, I don't know it).

JoshMST
04-22-05, 10:31 AM
I think you are right Remi. When doing some testing last night I was thinking about how possibly everything was put together, and how one card communicates with the other, and how the frame information is passed. Yes, we will not get super fast framerates at lower resolutions, and you are correct that the reason is the passage of info back and forth from the cards with the "measley" 1 GB/sec over the top connector.

Still, who can complain about 85+ fps at super high rez with AA turned on? I certainly can't!

One thing that I wonder is what communication protocol is utilized for the over the top connector? I would not be surprised if it was some HyperTransport variant (since NVIDIA is one of the leading manufacturers in this consortium). Then again, it could be something completely different and created only for this situation.