Network admins: Opinion on network rendering?

[Drakkon]

Graphics guy who does a lot of 3d work for us today omes by with hands me this document:
http://www.visualz.com/free/down_on_the_farm.pdf
Hes been asking about it for months now and I keep telling him i'm not inclined to let him do it just cause i know he will abuse it. However now upper management is asking what the possiblities are and they hear "cheaper" and "less time" so they want to investigate more. What they want to do is take every desktop in the company and install this "backburner" app so that they all become render nodes whenever our graphics dood needs to render out a movie.
So i ask you network people of Anandtech...what are your thoughts on this? good idea? bad idea? what are the disadvantages (going on "advantages" detailed in the document above)?

 

[Medunaweb]

"This is because rendering takes 100% advantage of both processors at all times."

I would assume that the other PCs on your network are used by other people for business purposes. When the graphics man wants to generate his new movie it would not just use the CPU in his system which is built just for rendering but all the system on this network that are running this program. Sounds great for that one user who gets to use it all, but the people on each of those system will notice their CPU load jump to 100% making what ever they are doing VERY slow and will more then likely get them all mad at you.

I would rather have the one graphics guy mad b/c it takes him all night to generate his movie then to have the other 100 employees mad at me b/c they think their systems are really slow.

Now if you are pressured into doing something like that I would try to isolate it at first to see how it runs. Put it on nonessential computers and see if the users of those complain about speed issues.

Or have it so the graphics guys only use it's features at night past 10pm so it doesn't bother other workers.

This will also put a large load on your network aswell. All that info being worked on, on each PC must be sent over the network. If they do it like SETI@home does it won't put hardly any load on your network. But if you have 100 people all sending video clips back and forth then you may see your network performance for other users on the network drop.

So I guess my conclusion would be to tell management this might be a great asset, but at the same time it may hinder our ability for other workers to get their work done. Therefore I recommend that we implement it on 3 or 4 PCs and see how it affects the users of those systems. If that seems to work with out a problem then try to implement it across 24 nodes. If that starts to raise problems then maybe cut it back and let them use 12 nodes, if it still has no problems then up it to 100 nodes and so on.

 

[netsysadmin]

Well something like that would cause me issues even if used in the middle of the night since I am running backups to tape over the network. Why not just set him up a cluster of cheap computers instead?

John

 

[skyking]

That sounds like a good idea, if it were not for the OS licenses. Too bad they did not make an application for unix for this.............

 

[eigen]

Originally posted by: skyking
That sounds like a good idea, if it were not for the OS licenses. Too bad they did not make an application for unix for this.............

Sure they do, at least for linux, just search for linux rendering cluster optionally include heterogenous to make sure you can use whatevers lying around.

 

[Garion]

No offense to previous poseters, but why not? It seems like a reasonable app, and I would imagine that the amount of network traffic during the renders would be minimal. Most PC's waste 95% of their CPU time anyhow - Might as well get something out of it. That's the whole concept of Seti, Folding, etc. There's no reason for a company not to take advantage of it, assuming it doesn't impact the normal computing on the machines it's installed on.

If you're worried about it, you can always set it up to start at 6 PM and stop at 7 AM so that it just runs overnight - That would minimize the impact.

- G

 

[Boscoh]

I agree.

I've seen these things in action, and the network traffic is really only significant when the nodes are transmitting or receiving a frame. In my experiences it takes them quite a while to render one frame. One of our girls that's doing animation rendering on a Mac G4 says it takes her close to 30 minutes to render one frame. That time is dead-time for her, because she cant do anything on her Mac while that program is rendering.

The only problem I would have is if this program uses the CPU all the time instead of when the CPU is idle. I wouldnt want the thing impacting normal business, but if Sally is on the phone with a customer and not using her PC, and Joe is out to lunch, then that program can use their PC's all it wants.

Like it's been said before, if it's a problem just set the app to launch after business hours and end before the start of the next day.

 

[Drakkon]

what about if the network is domain controlled and thus everyone logs off when they leave? I guess have to give him an account that can only log in between certain times with guest access and limited program access or autostart just that program? or is there a better way with Windows server 2k3 to allow this sort of thing to happen?

I was no way going to let him use comps during business hours...we already resolved that and he understands theres no way that will ever happen. Just too many complications if it effects network traffic or if the prog locks up the comp while someones doing something important or starts to slow down office apps for any reason. There going to build him a cluster (5 or so machines) it sounds like but its articles like this that keep him bugging me about using EVERY computer...greedy graphics people 😛

 

[Garion]

No offense, but the reason that we all have jobs doing networking is that people need us to make them more productive. It sounds like this graphics gy has a legitimage business need that will make him radically more productive without affecting anyone else or spending any money. Sounds like a no brainer.

You might look into that app a bit - It might be able to run as a service, so it wouldn't require the user be logged in to each computer and you wouldn't have to change your policies on logging everyone out overnight.

- G

 

[Boscoh]

If it's a system service, it shouldnt matter if a user is logged on or off, it should still run.

Personally I make sure my users dont shut down their computers when they leave. I have nightly antivirus and other system checks that run, so it's important that users do not shut down their PC's.

 

[ToeJam13]

There are a few things to look out for, but otherwise this shouldn't be too much of an issue.

[*]CPU - many network farm rendering programs can be configured to run in a "background mode". This is usually nothing more than switching themselves from the default CPU priority to a lower one, or giving themselves a higher "nice value". As such these programs will use only the CPU resources left to them by other programs.

[*]MEMORY - although these programs are good at sharing CPU time, they are poor at sharing memory. Even if you could limit physical memory allocation priority, the result would be that of the rendering program swapping like crazy. As such, you will need to have enough physical memory for both general office productivity software as well as the rendering program. This may require you to add additional memory, up to 1GB, for rendering.

[*]HARD DRIVE - luckily, network farm rendering programs don't keep a lot of information on the local hard drives. They keep just enough to do their tiny part of the job and then send that back to the master rendering server. As such, you won't need to upgrade your hard drives.

[*]NETWORK - depending on the rendering application, your network may already be fine for the job. If you're using switched 10Mbps (or better) per desktop, you'll see minimal impact. However, if you're using shared hubs, even if they are 100Mbps, other users will notice when somebody is sending their rendered frames.

[*]OS - I wouldn't try something like this on a Win95/98/Me desktop. They just can't handle the resource sharing the way WinNT/2K/XP or Unix can do. Users will compain of sluggish responce on their desktops. Also, you'll need a real multiuser OS in order to keep rendering applications running even after the employee logs off their machine for the night.

 

[Cheetah8799]

I think you need to educate the management about the side effects of a project like this. If the graphics guy starts rendering something that requires every computer in the company to do some work, what will happen to those other computers? Will they slow down a noticable amount? Will the users get pissed that their machines are slower because of this one guy?

Maybe you should investigate alternatives. How about a Linux cluster? I realize it is more money than they may want to spend, but causing problems for every pc in the company is a big issue.