External Graphics Cards
I was wondering, is it possible to have external graphics cards ?
Like a graphics card in a little box with a firewire connection and a monitor out or something. Can firewire handle the bandwidth ?
and if it cant, why arent we using DVI ports as data ports ? if they are that much faster (as opposed to firewire).
In fact if this concept was possible it mean all computers would have upgradeable graphics. And graphics upgrades would be as simple as plugging in a mouse.
We have external sound cards, why not external graphics...
Like a graphics card in a little box with a firewire connection and a monitor out or something. Can firewire handle the bandwidth ?
and if it cant, why arent we using DVI ports as data ports ? if they are that much faster (as opposed to firewire).
In fact if this concept was possible it mean all computers would have upgradeable graphics. And graphics upgrades would be as simple as plugging in a mouse.
We have external sound cards, why not external graphics...
Comments
Originally posted by AsLan^
I was wondering, is it possible to have external graphics cards ?
and if it cant, why arent we using DVI ports as data ports ? if they are that much faster (as opposed to firewire).
It is certainly feasible, and has been done before ( SCSIgraph, very old graphics card for the mac plus ).
In modern times it seen when you run VNC or Terminal Services over a network ( X windows predates this ), which is a way to seperate your application running machine from your graphics processor.
The negative to these systems is primarily speed. You cant run intensive graphics processes on them very effectively. But they are fine for business apps. Because of their limited market they also cost more. If there was a general, popular solution I dont think it would be much more expensive.
Firewire 400 is fast enough, and a proof of concept would be a graphics card driver that turned an AIO machine into a second monitor for another machine.
DIV has much higher bandwidth ( 3gbps v .4gbps ) than firewire, and that is per channel ( Apples new nvidia card is dual channel ). But the trick with doing graphics is to send as little information as possible untill the last possible moment. So you can get away with firewire for less demanding apps because the 3gbps of DVI is having to refresh every pixel 80 times a second.
We dont use DVI as a data port because it is a low level interface. Firewire provides lots of usefull things, like more than one device per port, isochronous transfers and more. DVI is just a bit shoveller. Dedicated ports when it makes sense, general purpose for other scenarios.
Firewire wont provide the basis for a powerful graphics solution. However, Hypertransport could. I dont believe that a specification has been created for external hypertransport buses, or even sockets for internal ones. But I think it is coming. They are busy just making it work well for CPUs atm. PCIe is also a potential candidate. But the nice small buses which are good for external use arent fast enough to be considered an upgrade over AGP.
Can somebody try networking two macs via tcp/ip over firewire then streaming uncompressed video via video lan client or forwarding an x session with a 3d game (like tuxracer or something) over the connection to see how it looks on the other side.
Would this be an effective test ? I know it has a lot to do with the efficiency of tcp/ip but it might give some indication.
how pci works
A 66mhz pci bus (agp) has a data throughput of 512 MBps.
If firewire has a throughput of 400 mbps, shoudlnt this be close to enough to allow some kind of similar performance between firewire 400 and 66mhz bus speed of agp (512 mbps) ?
Originally posted by AsLan^
According to howstuffworks.com
how pci works
A 66mhz pci bus (agp) has a data throughput of 512 MBps.
If firewire has a throughput of 400 mbps, shoudlnt this be close to enough to allow some kind of similar performance between firewire 400 and 66mhz bus speed of agp (512 mbps) ?
No. PCI is 512 MBps (with a big "B") vs Firewire's 400 Mbps (with a little "b"). There's a big difference there. Big "B"s mean "Bytes" whereas little "b"s mean "bits". Firewire has a bandwidth of 50MBps (with a big "B"), which is a little less than 10% of PCI's bandwidth.
Originally posted by Whisper
No. PCI is 512 MBps (with a big "B") vs Firewire's 400 Mbps (with a little "b"). There's a big difference there. Big "B"s mean "Bytes" whereas little "b"s mean "bits". Firewire has a bandwidth of 50MBps (with a big "B"), which is a little less than 10% of PCI's bandwidth.
Well, thats a shame then, I was hoping there would be a way to process the graphics away from main unit.
Originally posted by powermacG6
Actually, is it possible to connect to a PCI slot with a ribbon interface? Or does the wire lenght become a problem?
While I'm far from a hardware engineer... I do remember reading posts from people who seemed much more knowledgeable on the subject who stated something to the effect that mobo design was a very precise business. For example, the number of cementers the memory banks are located from the CPU socket tend to be vital and I'm sure PCI has similar issues.
I also remember back when Steve first reduced the number of PCI slots in the pro line (and the enormous amount of hubbub that followed) when people started talking about external PCI boxes and one of the main problem was the fact that external PCI boxes could only be used for cards that didn't have enormous bandwidth needs. (video card for example would be out of the question) - This was YEARS and YEARS ago so who knows if this is still true (but I'm assuming it is)
Dave
Originally posted by powermacG6
Actually, is it possible to connect to a PCI slot with a ribbon interface? Or does the wire lenght become a problem?
I don't know but you may have to use some converter between the parallel AGP bus and convert it to a serial bus and pump that through an optical fiber cable.
...why not offload the graphics and hot components to a little white Cube/alu box/unit? Have the CD/DVD in the monitor.
...why not have a box that you could indeed stack two Nvidia 6800s in ?
Split the specs/components to produce an ergonomic design aka the Anniversary Mac 20th.
Alu or white that and you've more or less got what's being spoken about in rumors.
It would be nice to augment the graphics capabilties of a desktop/laptop with a separate unit/box that you could plug in...much like you do an extra hard drive.
Imagine having external graphics cards like drives that sit on your desk. Plug 'em in and you get a 6800 plugging into your eMac/iMac/laptop for kickass performance.
Is this possible? Could this be done via a hug pluggable version of AGP? PCI Express?
Addressing Nvidia's 'SLI' mode graphics:
Will Apple address ultimate graphics to go with the MP 'Antares' processor?
There is plenty of room in the PowerMacs. Lord knows the tower is tall enough...
Even mid-range 6600 GT cards have SLI capability built in. So, as long as your motherboard is SLI capable then you can add graphics card performance to your 'stack' as funds allow...
People?
Lemon Bon Bon
Originally posted by Whisper
No. PCI is 512 MBps (with a big "B") vs Firewire's 400 Mbps (with a little "b"). There's a big difference there. Big "B"s mean "Bytes" whereas little "b"s mean "bits". Firewire has a bandwidth of 50MBps (with a big "B"), which is a little less than 10% of PCI's bandwidth.
However, normal PCI ( 32bit, 33mhz ) is only 133MBps. So firewire 400 is a but less that half the speed, and firewire 800 is getting there. This is relevant because plenty of people are using Quartz Extreme with PCI radeon video cards and finding it to be pretty good. GigE also exists on the pro machines. You dont have to use TCP/IP, ethernet itself has little overhead. That could pretty much match PCI. Its not going to be much for gaming, but for 2d apps, I think it would be fine.
Originally posted by Lemon Bon Bon
Imagine having external graphics cards like drives that sit on your desk. Plug 'em in and you get a 6800 plugging into your eMac/iMac/laptop for kickass performance.
Is this possible? Could this be done via a hug pluggable version of AGP? PCI Express?
I dont think it is going to happen ( for consumers ) with any of those parallel interfaces. But when hypertransport gets an external bus, it will be possible to plug in a PCIe bridge cihp, and then plug two PCIe cards into that ( current HT bridge chips support upto 32x worth of PCIe ), if you wanted more you might have to use a more expensive bridge, or use 8x PCIe to get four cards. nvidias sli ( if I remember correctly ) uses one card in 16x and one card in 8x, so that you can have some little PCIe slots left over.