Graphics Wars III - SLI blather

Slutmonkey57b

Well as we've all exhausted ourselves bashing each other over the whole 6800 vs X800 debate, I thought I'd stir up the pot again by pointing everyone to Tom's evaluation of the SLI question, as Nvidia have been crowing over ATI's apparant recent performance loss and have effectivly embarrassed ATI into developing their own SLI version.

The conclusion for the short of attention span is that SLI is
a) Only for the rich
b) Buggy as hell on the Motherboard side of things
c) Only give you a boost on the very latest shader-intensive games (like Doom3), and usually only at the highest res. with AA and AF on
d) Is only compatible with a VERY limited number of games.
e) Will actually slow your system down (or **** it up) if the game isn't on NVidia's list.
f) But you can mix and match ATI and Nvidia cards and still have the system run (buggy).

So, take what you want from that. I said a few months ago that despite all the marketing blurb positioning it as the "budget" or "slow" upgrader's dream, it's really just another ultra-high end headline grabber for the ultrarich/verystupid (delete according to your own opinion). Tom's would seem to agree though you might not trust them yourselves.

Thrasher

Agree with this 100%. In spite of the ridiculous excitement over running multiple GPU cards on the same motherboard, the realistic arguments for SLI are very few!

The two target markets:
1) Rich game enthusiasts who have to get the highest benchmark scores: How many of these gamers are realistically going to buy a special SLI mobo and TWO expensive GPU cards?

2) Slow upgraders: The rate at which GPU performance is increasing coupled with the driver/software advances (i.e. DirectX 10, 11 etc.) will mean that these users will be expected to fork out for a new, expensive mobo NOW (+PSU?) - and when they finally get round to buying a second SLI card, performance & functionality will be nowhere near cutting edge.

/T (purchaser of two second-hand SLI Voodoo2 cards in 1999)

po0k

Slutmonkey57b wrote:

Well as we've all exhausted ourselves bashing each other over the whole 6800 vs X800 debate, I thought I'd stir up the pot again by pointing everyone to Tom's evaluation of the SLI question, as Nvidia have been crowing over ATI's apparant recent performance loss and have effectivly embarrassed ATI into developing their own SLI version.

The conclusion for the short of attention span is that SLI is
a) Only for the rich
b) Buggy as hell on the Motherboard side of things
c) Only give you a boost on the very latest shader-intensive games (like Doom3), and usually only at the highest res. with AA and AF on
d) Is only compatible with a VERY limited number of games.
e) Will actually slow your system down (or **** it up) if the game isn't on NVidia's list.
f) But you can mix and match ATI and Nvidia cards and still have the system run (buggy).

So, take what you want from that. I said a few months ago that despite all the marketing blurb positioning it as the "budget" or "slow" upgrader's dream, it's really just another ultra-high end headline grabber for the ultrarich/verystupid (delete according to your own opinion). Tom's would seem to agree though you might not trust them yourselves.

Read anandtech's report here.
re: a) You get what you pay for. There is a market for it. 2x 6600GTs cost less than one 6800Ultra, and outperform it in many cases. Link (bottom of page)

re: b) I've seen reports to the contrary. Production Asus and Gigabyte SLI boards seem to work fine.

re: c) That's due to CPU limitation at lower res. SLI is a stop-gap measure until we have proper multi GPU tech. 3D rendering scales linearly. There is overhead with SLI, but if you can pull 100+FPS in HL2 and Doom3 at 1600x1200 FSAAx4 AFx8, in full detail, today, why not?

re: d)

From [url=]here[/url]:
How will applications take advantage of the SLI technology?
SLI technology is application transparent and is enabled through the graphics drivers. Many DirectX and OpenGL applications can take advantage of SLI. When two graphics boards are configured with SLI technology, applications that have the ability to scale will automatically be able to take advantage of performance improvements with no modifications.

nVidia engineers have included profiles for the top100 games to optimise the setup (Alternate frame or Load-balanced rendering) for each.
The SLI setup is essentially transparent to the games.
A drop in performance of an SLI setup relative to one of the same cards on its own is due to the SLI overhead in continuous frame games, where they use things like blurring effects, where the previous frame in the card's framebuffer needs to be used to create the next frame. In the AF setup, the data has to be moved across the SLI interface to the other card. Using Load Balancing on such games shouldn't see any penalty.

re: e) Again, if the game was written correctly, the presence of an SLI setup will be transparent to the game, as they're operating at different layers of the rendering process.

re: f) You're last point makes no sense.
You can't pair an nVidia card and an ATI card in SLI mode.
Please stop talking out of your arse//reading The German Dentist

Slutmonkey57b

a: the 6600GTs that support SLI are only just being produced. In fact a lot of the reviewers couldn't get hold of 6600GT's to run previews on. A card bought a couple of months ago will NOT support SLI. So if you bought a card already you will not be able to match it with another in SLI mode, which was supposedly one of the selling points of the whole thing.

b: At the time of writing, my comment was correct. Also, production boards are non-existant in retail channels, just like the x800 and 6800 "press edition" cards.

d:

nVidia engineers have included profiles for the top100 games to optimise the setup (Alternate frame or Load-balanced rendering) for each.

This is exactly why SLI is going to cause problems. Game writers and driver writers are always constantly "hacking" their way around systems to get a couple of extra FPS, or a better render out of their engine. Introducing SLI on top of that when it's not explicitly tied into the Directx or OpenGL spec is going to lead to more bugs, more patches, more driver releases as the game writers, OS writers, and driver writers hack their way arouind each other's systems.

IMO this is a bad thing.


e: There is no "correct" way to write a game engine.

f: Where in the Tom's article does it suggest you can run both in SLI mode? Nowhere. But you can install both cards in one machine, and not have the whole system crash. This is an impressive achievement. Read first, flame later please.

I'm not here to debate the technical nitty gritty, as frankly I'm not an engineer, but to me the whole business of SLI smacks of high-end "marchitecture" rather than a useful solution. It's being portrayed as a boon to the budget builder, when it clearly isn't. The budget builder, first, does not spend €200+ on a mobo. Second, they upgrade on a 2-4 year cycle. I just upgraded from a PIII to a A64 - after 3 years my upgrade options on a pIII system were zilch because the tech was obsolete. Since GPU's have to be *matched* in SLI, what are the chances of the budget upgrader finding a card to match their 3 year old card when they next come to upgrade? Slim I think you'll agree.
Conversely, the people who do have the money to spend on an SLI setup already have all the power they need, if not all the power they could want.

The tech of SLI is all well and good (up to a point, as I stated above), but the purpose of SLI is certainly not to help the budget user. It's a headline grabbing press release. Though it certainly made a mockery of Tom's "principled" stand against reviewing pre-production, buggy, unreleased kit. Not that we expected that of course.

jozi

I think its a load of crap. Even if i had the money i dont think id adopt it.
How can you not be happy with the performance you get of a 6800gt/ultra in the first place?
Its just a way for gamers (or who ever else) to boast, look i got 2 6800ultra's my graphics are better than yours......
Just my taughts

Jozi

uberpixie

jozi wrote:

Its just a way for gamers (or who ever else) to boast, look i got 2 6800ultra's my graphics are better than yours......
Just my taughts

Jozi

Yeah but that is what it's all about: the ultimate penis extension for hardware geeks....

po0k

Slutmonkey57b wrote:

a: the 6600GTs that support SLI are only just being produced. In fact a lot of the reviewers couldn't get hold of 6600GT's to run previews on. A card bought a couple of months ago will NOT support SLI. So if you bought a card already you will not be able to match it with another in SLI mode, which was supposedly one of the selling points of the whole thing.

If the card has an SLI connector it'll run SLI.
One of the requisites is that the two cards have the same BIOS version, and have similar memory (~= the requirement for card from same vendor).

b: At the time of writing, my comment was correct. Also, production boards are non-existant in retail channels, just like the x800 and 6800 "press edition" cards.

Well it's not correct now.
Also, the bigger review sites will get production samples of the boards. You may not see them in the retail channel for another 1-3 weeks due the need for the manufacturer to ramp up production and have sufficient numbers to ship. Then there is the actual shipping time required.

d:
This is exactly why SLI is going to cause problems. Game writers and driver writers are always constantly "hacking" their way around systems to get a couple of extra FPS, or a better render out of their engine. Introducing SLI on top of that when it's not explicitly tied into the Directx or OpenGL spec is going to lead to more bugs, more patches, more driver releases as the game writers, OS writers, and driver writers hack their way arouind each other's systems.

IMO this is a bad thing.

Again, the engine writers must work within the framework of the chosen API(s).
The API is an intermediate level between the game and the driver/card.
If you write a game for DirectX9, it'll work on any compliant "system".
As far as the API is concerned, a pair of SLI cards is indistinguishable from a single card, as the SLI work distribution is dealt with on a lower level.
To draw a comparison, look at the OSI 7layer model for networking.
Each layer does its stuff and passes the output to the level above/below it.
Each layer doesn't have to be aware of what the other layers are doing. It's all abstracted.
This is the way things have been done since the 2nd/3rd gen of cards.
In the 1st/2nd gen, each card family had it's own API. See: PowerVR, 3Dfx, S3

e: There is no "correct" way to write a game engine.

There is. Adhere to the standard. Just like any other type of programming.

f: Where in the Tom's article does it suggest you can run both in SLI mode? Nowhere.

Youre orignal point implied having two cards in an SLI system, ie linked in SLI mode. It's not our fault if you can't make a clear point.

But you can install both cards in one machine, and not have the whole system crash. This is an impressive achievement.

How is this more impressive than having 2 PCI cards or 1PCI and 1 AGP card in systems 5 years ago?

Read first, flame later please.

This is hardly flaming

I'm not here to debate the technical nitty gritty, as frankly I'm not an engineer,

Then why critique a technical topic?

but to me the whole business of SLI smacks of high-end "marchitecture" rather than a useful solution. It's being portrayed as a boon to the budget builder, when it clearly isn't. The budget builder, first, does not spend €200+ on a mobo. Second, they upgrade on a 2-4 year cycle. I just upgraded from a PIII to a A64 - after 3 years my upgrade options on a pIII system were zilch because the tech was obsolete.

I'm in a similar situation, but I've upgraded my Gfx card approximately every 12-18months.

Since GPU's have to be *matched* in SLI, what are the chances of the budget upgrader finding a card to match their 3 year old card when they next come to upgrade? Slim I think you'll agree.

I don't think the majority of gamers, budget or otherwise, will wait 3 years without upgrading some part of their system.
There are still GF4 an GF FX cards to be found in retail, though they may be hard to track down. Failing that, second-hand or eBay are good resources.
I haven't bought a retail card in 4 years.
If the two cards are reasonably similar, they can both be flashed to the same BIOS level in most cases, and if their memory differs, you can just adjust the clock on the faster one to bring it inline with the slower, or overclock to match.

Conversely, the people who do have the money to spend on an SLI setup already have all the power they need, if not all the power they could want.

You can never have enough power.

The tech of SLI is all well and good (up to a point, as I stated above), but the purpose of SLI is certainly not to help the budget user. It's a headline grabbing press release.

My opinion: I don't agree. I think in the next 3 months the scene will change. The kit required to make an SLI system at the moment is expensive, but it is also very very new. I remember seeing somewhere that nVidia mentioned releaseing SLI packs, ie 2 cards at a reduced price compared to buying them seperately.
Also, buying one SLI card now, and another in 6-12 months time isn't too far fetched for a good increase in performance (you'll also be increasing the resolution and detail at the same time in most cases).

Though it certainly made a mockery of Tom's "principled" stand against reviewing pre-production, buggy, unreleased kit. Not that we expected that of course.

I tend to take what Tom says with a pinch of salt. IMHO, he's a bit of a "tabloid" reviewer.

And I'd like to stress that I amn't flaming you. I merely disagree with you and would like to point out where you are wrong/mis-informed, particularly since your first post might give the impression to other posters that what you say is true without fault.

Before anyone says it, I'm by no means an nVidia phanboi, I do own an nVidia card, but would happily take an ATI card if someone offered it.
Two X850s in SLI would be rather spiffing in HL2.

po0k

uberpixie wrote:

Yeah but that is what it's all about: the ultimate penis extension for hardware geeks....

Just because you can't afford an uber setup

If I could play new triple-A games at max detail, quailty and res at a steady 100+fps, I would.
SLI is a solution for those who can afford it.

If a car manufacturer brought out a powerful, comfortable and reliable car, there are people who'd buy it. The cost (Initial, running, raod tax and insurance) might be large, but it would have a market.
Some would be compensating, but all the owners would enjoy the quality ride.

Look at all the Mercs, BMWs, Lexuses etc knocking about.

Bass.exe

Getting a new rig... going SLI. I'm not getting 2 6800 Ultras however... just 1 6600GT... for now. I think the advantage of SLI (apart from uber-high-end gaming) is that you can upgrade 6 months or a year down the line, when you have money. That's my plan anyway.

(Lexuses..... Lexii? )

TheDuke

Yeah but that is what it's all about: the ultimate penis extension for hardware geeks....

oh... sore you're telling us you don't need a SLI setup ... well good for you mate... hung like a donkey then are we ... ...