multiple video cards

[bendorsey]

Hi Folks:

In browsing new computers of various brands I see some offered with 2 and even 3 video cards.
1. How does that work?
2. Is it advantageous to Trainz?

Thanks,

Ben

 

[JCitron]

Hi Folks:

In browsing new computers of various brands I see some offered with 2 and even 3 video cards.
1. How does that work?
2. Is it advantageous to Trainz?

Thanks,

Ben

1. The video cards are bridged together so they work together in tandem, giving them more memory and a faster speed more or less. It's not double the speed but faster overall. There are two similar, but slightly different technologies from the two big players. ATI has their Crossfire, while NVidia has their SLI.

Theoretically speaking, it could be double or triple the speed, but due to some scaling and buss bandwidth issues, it works out to be 1/3 faster instead of 100% faster for two cards, with three cards being that much again more. There are other issues as well due to crosstalk noise, which causes what is known as micro-stutters. This can be seen as very slight pauses in what would be otherwise a smooth video output. There are ways around it to make this less noticeable, such as adjusting frame rate limiters, and V-sync, but it isn't perfect. Some people find that 3-cards is better at this than 2-cards. This is probably due to the harmonics.

2. Not at the present time, though it's been mentioned again as a someday thing. I actually brought this up during the early Kick Starter days, and there was quite a bit of interest in it. N3V has sort of ignored the issue, but someone brought it up again in the new Trainz Support blog-thing, and the answer is it's in the cards for the future in so many words.

Do I have this? Nope. I can't afford a 2nd video card.

John

 

[pcas1986]

Maybe you should ask Ian Woodmore. He posted recently that he has two GTX GeForce 780Ti cards and is getting 120fps on some routes. The rest of his system isn't too shabby either.

I have a single 780Ti and generally get about 60-61fps although it does drop a bit when there is an obvious load.

The cost of another card is a bit prohibitive for me.

 

[pdkoester]

it really does not double the memory.

 

[bendorsey]

So is it safe to say multiple video cards will speed up any program (Trainz included) to some extent but do the best speed up job on programs designed for multiple cards (which T:ANE might be sometime in the future)?

I've been toying with the idea of replacing my (5 year old) Alienware Aurora tower with the new Alienware Area-51 tower (that weird triangular thing) as a Christmas present from me to me (the best kind, lol). One option is triple NVIDIA GTX TITAN X cards with 36Gb GDDR5 (gotta be some serious speed in there somewhere).

Ben

 

[malikrthr]

Nice. I think that would be a great build to handle TANE, or any game or simulator that you use. With that graphics power, it should run as smooth as butter with no stutter.

 

[bendorsey]

It better, lol.

Like I said a major $$$ outlay but what the heck - its all I do. No longer have a model railroad. Tore it out since we are moving. Took 15 years to build but only 2 weeks to dismantle (bummer of the first magnitude).

Other options are:
Intel i7-5960X 8-core processor overclocked to 4.0 Ghz.
32 Gb RAM
32 inch ultra HD monitor
Two 500Gb SSD's in the 2-drive RAID configuration.
Two 6-Tb SATA hard drives for storage.
1500 watt power supply.
The usual odds-n-ends.

Total is around $10,000 (told ya I was crazy).:hehe:

Ben

 

[LNERlover5]

Something to consider is that presently, VRAM does NOT stack. So having 3 GTX Titan X's does not equate to 36GB's of VRAM. THe way it works is each card renders each alternating frame, so what you have is 12GB PER frame, not 36GB per frame as you could expect. With DX12, we will begin to see multicard solutions render frames together (so two cards would render half a frame each for example, top and bottom etc), this will effectively double the available VRAM as expected as both cards can work on the same image. This will require Trainz to be rewritten for DX12 however.

As for the rest of the system, make sure that 1500W PSU is 80+ Titanium given the cost and output! You might want to consider dropping the RAID SSDs for a single Intel 750 NVMe drive, as this will be a single solution and quite a bit faster as they are based on PCI-E rather than SATA, delivering around 2GBs per second read speeds, which is just obscene. Go for a good motherboard from a reputable brand such as ASUS with their ROG or WS boards (For the 5960X, the socket must be 2011-V3). etc etc.

Jack

 

[bendorsey]

Hi Jack:

Thanks for the info. I've never heard of the 750 NVMe drive but then I'm not really computer savvy at the hardware level (any level for that matter, lol). Will mention it to the Alienware gents when the time comes.

Yes - I realize each video card comes with its own 12 Gb of (dedicated) RAM which does not really connect (or act like) one contiguous block of 36Gb of RAM.

No motherboard options that I know of. Ditto power supplies other then a smaller wattage one.

One odd shortcoming is it can only have 1 optical drive. My 12 year old Gateway had 2. Not a biggie but having 2 definitely makes copying this-n-that a breeze.

Obviously I have some serious negotiation to do between now and then with Mrs. Santa Claus (da wife, lol).

Ben

 

[whitepass]

Do you have a big 4k monitor that needs 3 video cards? I have a 24" 1920x1200 and found I only need one card.

 

[johnwhelan]

It better, lol.

Like I said a major $$$ outlay but what the heck - its all I do. No longer have a model railroad. Tore it out since we are moving. Took 15 years to build but only 2 weeks to dismantle (bummer of the first magnitude).

Other options are:
Intel i7-5960X 8-core processor overclocked to 4.0 Ghz.
32 Gb RAM
32 inch ultra HD monitor
Two 500Gb SSD's in the 2-drive RAID configuration.
Two 6-Tb SATA hard drives for storage.
1500 watt power supply.
The usual odds-n-ends.

Total is around $10,000 (told ya I was crazy).:hehe:

Ben

Hold off a few months, AMD have changed the video card market with a different type of memory access, nVidia are expected to have something very similar out shortly so the top of the line video cards will

change with performance improvements.

Cheerio John

 

[bendorsey]

This is not gonna happen until around Christmas time or a little after the new years so I have some time to look around and see what new alternatives might be offered between now and then.

As you can guess this is offered in several versions with each version having oodles, heaps, and gobs of choices for this-n-that. I tend to buy the top of the line mode and in this case it is only offered with triple video cards. Ditto Ultra HD monitors (32 inch in my case)

What the heck - its only money and ya can't take it with you - (Government won't let you). :hehe:

Ben

 

[johnwhelan]

This is not gonna happen until around Christmas time or a little after the new years so I have some time to look around and see what new alternatives might be offered between now and then.

As you can guess this is offered in several versions with each version having oodles, heaps, and gobs of choices for this-n-that. I tend to buy the top of the line mode and in this case it is only offered with triple video cards. Ditto Ultra HD monitors (32 inch in my case)

What the heck - its only money and ya can't take it with you - (Government won't let you). :hehe:

Ben

Sounds good to me currently the memory on nVidia cards runs through an interface, AMD latest have widened the interface by a factor of something or other

so this week they are the fastest on the planet however Trainz appears to be optimised for nVidia and given TANE's hardware requirements I'd have a look to see if nVidia have the new memory interface before purchasing.

Cheerio John

 

[bendorsey]

I've been looking on the Alienware site pretty much weekly (to drool of course) and they seem to change what is and isn't offered quite often so by the time I get serious about buying one a lot may have changed towards newer and better options.

Meanwhile I best go do the dishes. Gotta keep Mrs. Santa Claus buttered up, lol.

Ben

 

[PC_Ace]

Ben. The latest Alienware rigs have just been announced today, with the X51 desktop versions now sporting Skylake processors and optional liquid cooling.
http://www.cnet.com/products/alienware-x51-2015/

NVidia's roadmap shows some intriguingly re-vamped Pascal cards which should become available in 2016. These will also feature the High Bandwidth Memory that AMD is dining out on with its current top of the line cards.
Cool news is that in the Q&A area, N3V have confirmed that they will indeed eventually provide future support for multi-GPU Crossfire and SLI rigs.

 

[johnwhelan]

Ben. The latest Alienware rigs have just been announced today, with the X51 desktop versions now sporting Skylake processors and optional liquid cooling.
http://www.cnet.com/products/alienware-x51-2015/

NVidia's roadmap shows some intriguingly re-vamped Pascal cards which should become available in 2016. These will also feature the High Bandwidth Memory that AMD is dining out on with its current top of the line cards.
Cool news is that in the Q&A area, N3V have confirmed that they will indeed eventually provide future support for multi-GPU Crossfire and SLI rigs.

From the chemistry point of view just remember that water is known as the universal solvent and it time it will dissolve anything.


Translated this means it really likes to leak and if it doe its not nice inside your PC.

Cheerio John

 

[bendorsey]

Hi John:

I don't think that is the same model as I'm going to buy - the one I want already has liquid cooling.

As for leakage - I have a 5 year old Alienware Aurora Tower which at the time was the top of the line model. Its liquid cooled and I've never had a single drop of problems with it. Cooling is all controlled by the computer itself using several fans with variable speed, the coolant pump is also variable speed, and it has computer controlled vents as well. Temps are monitored here and there and I've never seen any over about 85 degrees F however - these are not microprocessor or video card temps.

In other threads I've seen folks able to monitor actual processor and video card temps (and get some frightening results with T:ANE). Is this something built into a computer? If not does it take a downloadable program to monitor those?


NEW SUBJECT

Ads often say "overclocked to (4.0 Ghz with turbo-boost") for example. I worked in electronics all my life so know all about Hertz (which were CPS when I started, lol). My question is when they say that does it mean the computer comes setup for 4.0 Ghz or can be setup for it with the proper software?

Thanks,

Ben

 

[JCitron]

Hi John:

I don't think that is the same model as I'm going to buy - the one I want already has liquid cooling.

As for leakage - I have a 5 year old Alienware Aurora Tower which at the time was the top of the line model. Its liquid cooled and I've never had a single drop of problems with it. Cooling is all controlled by the computer itself using several fans with variable speed, the coolant pump is also variable speed, and it has computer controlled vents as well. Temps are monitored here and there and I've never seen any over about 85 degrees F however - these are not microprocessor or video card temps.

In other threads I've seen folks able to monitor actual processor and video card temps (and get some frightening results with T:ANE). Is this something built into a computer? If not does it take a downloadable program to monitor those?


NEW SUBJECT

Ads often say "overclocked to (4.0 Ghz with turbo-boost") for example. I worked in electronics all my life so know all about Hertz (which were CPS when I started, lol). My question is when they say that does it mean the computer comes setup for 4.0 Ghz or can be setup for it with the proper software?

Thanks,

Ben

I know you were discussing this with John Whelan, but I'll jump in here too. Turbo-boost is a technology developed by Intel to allow for short to medium length bursts of faster than the set clock speed, based on a set ratio when the temps and load allows. My I7-3770k clocks in at 3.50 GHZ at the base. The Turbo-boost speed is 3.9 GHZ, and this is in addition to the overclocking capabilities built into the motherboard and the processor, which I have never done. When TB kicks in, I have seen the speed jump up to the 3.9GHZ range. This is generally used for video processing and 3d modeling as it gives the processor some extra horsepower to get through those arduous processes quickly. How this works in Trainz I've never monitored that to find out and that's got me curious too.

Yes, there have been some scary temperatures in T:ANE. This was brought up by a few of us in the developers forum, and there's a couple of things here that I can answer. From what we've been reading, though it sure scares the you-know-what out of us, these temperatures are okay for these video cards. The GTX780Ti, for example, is rated to operate at 83C. Anything above that temperature means the GPU will throttle down and slow down to cool off. The actual operating range is a lot higher and lower, but the optimal temperature is 83C. AMD run even higher in the 100C-plus range and do a similar throttling down to cool off.

The good news is this will not melt your processor, though it may appear to do that. The other good news is the current test builds are more efficient and the GPUs have been running much cooler than that. This makes us all feel great when we saw these results as our cards ran cooler and the program performs better, which means the code has been further refined.

John

 

[bendorsey]

Hi (another) John:

I dug out the original order form I got with my Aurora. It has an Intel Core i7 960 (3.2 GHz, 8Mb Cache). Yup - that's quite out of date today I'm sure - 5 years makes a heck of a lot of difference hardware wise - but would it have come with turbo-boost?

Yes - I've been following the heat issue with T:ANE in other threads. Sounds like better systems monitor temps and reduce clock speed to protect the hardware when necessary. Might tick some folks off when it happens but that's a lot better then a fried CPU or GPU I'd think.

As you gents can surmise I'm just trying to gather info here and there so I can make a better decision when the time comes. The last computer I really understood was a Commodore C-128 and that's not gonna help me much here.:hehe:

Ben

 

[johnwhelan]

Hi (another) John:

I dug out the original order form I got with my Aurora. It has an Intel Core i7 960 (3.2 GHz, 8Mb Cache). Yup - that's quite out of date today I'm sure - 5 years makes a heck of a lot of difference hardware wise - but would it have come with turbo-boost?

Yes - I've been following the heat issue with T:ANE in other threads. Sounds like better systems monitor temps and reduce clock speed to protect the hardware when necessary. Might tick some folks off when it happens but that's a lot better then a fried CPU or GPU I'd think.

As you gents can surmise I'm just trying to gather info here and there so I can make a better decision when the time comes. The last computer I really understood was a Commodore C-128 and that's not gonna help me much here.:hehe:

Ben

I'm not so sure that your i7 is that far out of date. The video cards have changed enormously but the CPUs aren't that different. The main improvement has been cutting the power consumption. I'd try dropping in a big Maxwell GPU first. TANE cpu usage seems lower than TS12 but its GPU usage is much higher so just drop in the biggest ugliest GPU you can lay your hands on. The current top of the line nVidia should do the trick or wait for the new ones coming in 2016.

Cheerio John