Solved

Memory bus width of a graphics card

Posted on 2006-05-27
2,536 Views
Hello guys,

If a card has memory bus width of 128 bit, is it good, bad, or so-so? How does the width make any difference onthe performance of a card?

Thanks,
Yurich
0
Question by:Yurich

LVL 32

Assisted Solution

In general the wider the better since the onboard processor can move more bits of data into and out of the onboard memory with each bus transaction.  These days 128-bit video cards are mainstream and I would say good.  In evaluating the performance, however, there are MANY factors other than simply memory bus width that need to be taken into account.
0

LVL 4

Assisted Solution

128 mb is acceptable. Clock rates are very important too.

Modern 3D graphics cards rely on the values of many variables in order to determine their speed. The most important of these variables are; clock speed, memory speed, and pixel processing volume. One very important card specification that is often overlooked is the number of pixel pipelines. If a card has 8 pixel pipelines, a clock speed of 400Mhz, and a memory clock of 1000Mhz, it is often slower than a card with 16 pipelines and lower clock and memory clock values.

0

LVL 70

Accepted Solution

Remember that a modern graphics card is really just another computer with a very specialized command set.   The CPU sends graphics commands to it, and it executes those commands.

So ... as with any computer, the wider the path to memory, the more data you can transfer between the GPU and memory on each access.  The memory clock speed determines how quickly those accesses occur -- so as noted above it's not a simple "just look at one thing" equation.

The reason it's so difficult to compare the absolute performance of graphics cards is the large number of variables involved:  the speed of the GPU (and even the same basic GPU is usually available in many different variants), the width of the path to memory (per this question), the speed of the memory, how much memory they have, the clock speed of the GPU, the number of pixel pipelines (paths to the actual graphics translator), the interface to the primary system's memory (AGP, PCI, PCI-X, PCI Express, and the various variants of those ==> AGP 2x, 4x, 8x; PCIe x16, x4, x8, x1, etc.), etc.

Bottom line:  "... is it good, bad, or so-so ..."  ==> of those choices, I'd say it's "so-so".   It's simply one factor (of many) that determines the overall performance of the graphics processor.   The current top-of-the-line cards all have 256-bit memory interfaces and 512mb of memory; but that doesn't in any way mean that a narrower memory interface or less memory is "bad."   Those top-of-the-line cards also have VERY fast GPU's that can utilize the faster interface and additional memory.  They also have commensurate price tags :-)
0

LVL 21

Author Comment

Thank you guys,
Yurich
0

LVL 70

Expert Comment

You're most welcome.
0

Featured Post

Suggested Solutions

Sometimes a user will call me frantically, explaining that something has gone wrong and they have tried everything (read - they have messed it up more and now need someone to clean up) and it still does no good, can I help them?!  Usually the standa…
this article is a guided solution for most of the common server issues in server hardware tasks we are facing in our routine job works. the topics in the following article covered are, 1) dell hardware raidlevel (Perc) 2) adding HDD 3) how t…
Excel styles will make formatting consistent and let you apply and change formatting faster. In this tutorial, you'll learn how to use Excel's built-in styles, how to modify styles, and how to create your own. You'll also learn how to use your custo…
Here's a very brief overview of the methods PRTG Network Monitor (https://www.paessler.com/prtg) offers for monitoring bandwidth, to help you decide which methods you´d like to investigate in more detail.  The methods are covered in more detail in o…