How much VRAM for dual monitor setup?

[norm_h]

A few days ago, I posted a question regarding the Dell Inspiron 9300

laptop (and got some good advice). As I plan on using a dual monitor

setup, someone suggested to have at least 256 MB video RAM. That much

VRAM, however, only comes with higher end GPUs, that will increase

heat and noise levels (and I'm aiming for quiet!). Searching the

archives, it seems that lots of peaple get by with 128 MB or even

less. Assuming that the laptop will have e.g. WSXGA resolution and the

external monitor would be a 21" (with matching resolution), would I

really need 256 MB or could I get by with less? Some in-depth

information on this issue (Google didn't come up with much) would be

really helpfull. Thanks - N.

[sean de merchant httpw]

I run 1600x1200x2 on a 128 MB card without issue.

 

Adding up the numbers:

 

1600x1200x2 = 3,840,000 pixels

 

3,840,000 pixels * 32 bits per pixel = 122,880,000 bits

 

122,880,000 bits / 8 bits per Byte = 15,260,000 Bytes

 

15,260,000 Bytes / 1024 Bytes per KB = 15,000 KB

 

15,000 KB / 1024 KB per MB = 14.6484375 MB

 

Hence, 16 MB will store all the pixels once. Add in that things get buffered and you might get multiple frames stored in memory leaving a pessimistic need for 64 MB. 256 MB is absurd overkill unless you are going to be gaming.

 

hope this helps,

 

Sean

[jbq]

What Sean said. 16MB is enough for 2 plain framebuffers, 32MB is more than you'll ever need for photo processing. For games it's another story, but then you're on the wrong site (and I'll argue that my PS2 does great with 4MB).

[kahheng]

Sean,

<p>

Adobe seems to think otherwise with CS2:

<p>

<a href="http://www.adobe.com/support/techdocs/331412.html">http://www.adobe.com/support/techdocs/331412.html</a>

<p>

They somehow suggest 128MB as minimum with their latest incarnation of Photoshop. I still can't figure out why and they've not actually been very detailed as to why a massive 128mb is needed for 2D work.

[scott_eaton]

Slow redraw times are likely the the result of using integrated video on older machines where shared system/video memory is a bottleneck. I've otherwise never seen PS7 hesitate on even older AGP 1x cards with 32meg memory.

 

I rate Adobe's advice on this topic up there with badgering people to use seperate physical drives when not necessary. You've consequently got a lot of Photoshop users ignorantly putting their scratch disk on external drives, and digging out 2.1gig Western Digitals to install in their machines and park their scratch file alongside their 'over-burdened' 160gig SATA's.

[norm_h]

Thanks everybody! That'll let me sleep a lot better. As I'm not using PS anyway (happy PictureWindowPro user), I'll go for some lower end GPU.

[steven_clark]

Just make sure you have at least a seperate card, onboard graphics is a nono.

[jasonsmith]

Scott

 

In your view what is an optimum HDD / Scratch Disc setup for photoshop CS/CS2.