The other likely upgrade scenario is that you have a system with integrated rather than discrete graphics, meaning the graphics are built into the motherboard rather than added on via a graphics card. People generally consider integrated graphics to be “free” since the graphics core is built into the motherboard’s northbridge chip. (Some notebooks mount a discrete GPU onto the motherboard outside of the northbridge, but we can ignore this since we’re focused on desktop cards in this discussion. The situation will get muddier over the next year or two as graphics cores migrate off of the northbridge and into CPUs.) But the downside of “free” is that, to some extent, you get what you pay for.
Integrated graphics tend to run a year or more behind their desktop counterparts in terms of technology and performance. For example, when the desktop RV730 chip arrived in September 2008, AMD had just finished releasing the 790GX IGP (integrated graphics processor). Whereas the HD 4650 has 320 unified stream processors (another term for shader computing blocks), the HD 3300 engine built into the 790GX has only 40, not to mention less than half as many transistors and a dependence on relatively slow system memory rather than dedicated graphics memory.
Mind you, the 790GX is still on the upper end of today’s integrated graphics scale. The volume leader in integrated graphics, Intel, has made considerable strides in its IGPs, but even its latest GMA X4500HD core within the G45 northbridge only supports 10 unified shaders. Quite simply, integrated graphics are designed for systems being used for productivity, online tasks, and perhaps light gaming. Only relatively recently have integrated graphics solutions been able to tackle high-def video decoding, such as Blu-ray movies, without bringing the PC to a practical stand-still, and just how many resources are still available for other tasks will vary considerably from chip to chip.
This leads us closer to the point. A lot has changed in the last year or two. Blu-ray is on the verge of being mainstream. Home theater convergence is inching toward being commonplace, helped along by Netflix and growing acceptance of downloading entertainment, including things like widgets being piped to LAN-enabled televisions. (See our story on HTPCs at http://www.tomshardware.com/reviews/windows-7-htpc,2349.html for some ideas on new hardware in this area.) As handheld media players and HD camcorders continue to gain acceptance, the need for systems to transcode mass amounts of high-def media continues to climb. Often, the issue comes down to convenience and usability. Systems from two or three years ago usually can do these things, but what’s the trade-off? Does the system become otherwise useless for hours while it chugs away on this one task? Does it require a mess of adapters and extra cables? Do you need to compromise on quality of output in order to complete the task? If your system’s existing graphics, whether integrated or aging discrete, are adversely affecting the quality of your potential media and/or entertainment experience, it’s time to update.