[MikoLayer]

mono, i will admit i know next to nothing about image editing. it just seemed the OP wanted a suggestion for a HTPC video card, and i doubt what you described would affect his decision... your reply was informative tho, it never occured to me you would need that much onboard memory for 2D purposes

 

[maarek99]

Monos information is wrong. You don't need that much information for displaying pictures. The zoom information is not stored in the vidcards memory. 32 megs for a 2d vidcard is way enough for displaying any current resolution&colour combinations.

 

[1UP]

Yah, it's balls - my 6800GT is no faster in Photoshop than a G450, UT2K4 on the other hand...

 

[Falqon]

Quote:

Originally Posted by mono Not to point fingers, but you guys dont' know anything about high-res image editing. The card needs 64+ MB of memory because when one edits, the entire image may be zoomed and the entire "virtual" image is then the resolution of the zoom factor. To keep the thing from being redrawn constantly (which can be very slow) it is necessary to have enough video memory to store the entire thing.

I'll point fingers, you have absolutely no idea what you're talking about. In PS the video card renders what is on the screen, no more. Which is why about 20 posts ago I asked for his system specs. More RAM and a faster hard drive is money much more intelligently spent for PS.

 

[mono]

maarek99,
then what is the cause of the greatly inceased "stuttering" when panning very large images? System had 2.5GHz CPU, 1.5GB of memory... certainly sufficient yet the video card change resolved the problem up until much larger images were used.

 

[mono]

Quote:

Originally Posted by Falqon I'll point fingers, you have absolutely no idea what you're talking about. In PS the video card renders what is on the screen, no more. Which is why about 20 posts ago I asked for his system specs. More RAM and a faster hard drive is money much more intelligently spent for PS.

I never claimed one shouldn't have sufficient memory or fast hard drive. I ask you same question as maarek99, how do you account for the performance difference in SAME SYSTEM when only change was video card?

If I am wrong I can accept that, but some kind of blanket statement about "renders what is on the screen" as a reason not to have suffficient memory to store more, does not seem correct. Another example-

I have a system out as a testbed, it has an ATI 8MB video card in it. It has about 110GB of free space on a new HDD, and 1.5GB PC3200 memory. If a 3200 x 2400 x 24 bpp image is opened, the whole thing selected, and dragged off the virtual canvas, it is clearly visable how the panning of the image produces blocky, somewhat stair-step like lags in image redraw. This does not happen (or is so fast it's not visually noticed) when the system had 128MB, and less so with 64MB, video card installed. Why? All other hardware remained same.

 

[mshan]

Hi mono:

This may be slightly off topic, but maybe you know:

With a video editing computer, is raw CPU power / CPU important or is memory bandwidth important?

 

[PFRfan]

mono, video card memory is primarily used for storing texture data in 3D apps. The difference in video card performance has to do with the speed of the processor rather than extra RAM. I've never heard of any off-screen 2D data being stored onboard the video card. What video card did you replace with what new card? If it's onboard, then granted, the performance will suffer. But if it's a late generation card with 32+MB RAM, then you shouldn't be able to tell the difference in screen redraw speed. You can tell image quality, color correctness, etc. But not speed. All of the redraws are handled by the CPU. Extra system RAM helps because it cuts out the hard drive.

 

[mono]

CPU and memory speed are both important, with caveats. CPUs with a lot of raw processing power like an Athlon XP, are not as fast as Athlon 64 or P4 with SSE2. Memory speed is very important regardless.

 

[mono]

Quote:

Originally Posted by PFRfan mono, video card memory is primarily used for storing texture data in 3D apps. The difference in video card performance has to do with the speed of the processor rather than extra RAM. I've never heard of any off-screen 2D data being stored onboard the video card. What video card did you replace with what new card? If it's onboard, then granted, the performance will suffer. But if it's a late generation card with 32+MB RAM, then you shouldn't be able to tell the difference in screen redraw speed. You can tell image quality, color correctness, etc. But not speed. All of the redraws are handled by the CPU. Extra system RAM helps because it cuts out the hard drive.

I'm well aware that video memory is used for 3D texturing. You write that it "has to do with the speed of the processor". Why then a difference when same processor is used? Or did you mean the GPU? In 2D, what GPU made in the last ~8 years or so can't do 30FPS or higher? Certainly the redraws I saw were far slower than 30FPS.

You write "late generation card with 32+MB RAM". Why? If I"m wrong, then shouldn't a 4MB card be just as fast ast 1024 x 768 screen resolution, providing the card is AGP, and has already demonstrated that it can display over 30FPS, for example by playing a video clip with no discernable lag? Even if it was struggling (which was not apparent for video playback), certainly faster than the image editing screen redraw, so GPU speed was not the bottleneck, or do you have more detail of what situation may otherwise cause it to be?

It's been common knowledge for a long time that more memory is needed for 3D, but where you can conclude that it's not possible to utilize more video memory than a 2D screen resolution, perhaps this is the central issue. What about overlays? Certainly that can be higher that the displayed screen resolution, how can an overlay write to video memory then?

 

[PFRfan]

The need for RAM in 2D display is directly related to the amount of onscreen information. OK - 32MB is extreme. 8MB is probably the realistic limit, but they haven't been making those in a LONG time, so 32MB being the current minimum, I figured that would do.

Check here - http://www.billsworkshop.com/techtips/ram.html.

Note the statement: "the extra RAM above 8MB is not used for 2D displays but is used for texture storage, a z-buffer space in 3D modes."

800x600 at 16bit color only needs less than 1MB video RAM. 800x600 at 32bit uses almost 2MB. As you scale up, you need more RAM. But this is only on-screen information - nothing is stored. 8MB of video RAM will be able to display 1600x1200x32 without difficulty. Older 8MB cards usually have cruddy RAMDACs, though.

AGP is only a way for the card to take advantage of system RAM when it runs out of it's own. It's slow, and is VERY rarely used. The main benefit of AGP over PCI is the higher bus speeds and wider data path.

 

[PFRfan]

And yes, I was referring to the graphics processor. Also, the speed of the video RAM can play a difference - another reason older 8MB cards are not so hot, as well as why shared onboard memory performs so slowly.

 

[PFRfan]

In regards to overlays, I'm not sure. But I think I agree that more RAM allows the overlay to work better. So if you're using FMV in overlay, then more RAM is probably useful. But for Photoshop it shouldn't make any difference.

 

[PFRfan]

A better article is here - http://www.dansdata.com/gz014.htm. Things have changed since either of these articles were published, but not in regards to 2D.

 

[mono]

Well the two linked articles basically rehash the simplistic view about resolution and bit depth, which is nothing new. I still respectfully disagree and think they simply aren't aware of the other benefits.

No explaination has been provided for the performance difference either. As already mentioned, cards "slow" at large image editing are sufficient to display >= 30FPS video playback, the memory bandwidth is clearly adequate for the screen resolution, but NOT for the image editing. This in itself clearly demonstrates (regardless of the reason) that more memory does help.

If it will satisfy some of you (and if I end up getting motivated enough to find it) I have an old Matrox G200 card somewhere that has a memory add-on card. I can keep entire system and video card, driver, etc, exactly the same and simply power down and pull out the memory card to change the amount of video memory used.... now if I can just find the thing, been a long time since I've seen it but it's around here somewhere.