About the built-in graphics
The BG7's integrated graphics are a no-lose proposition. They're true AGP graphics, so they make use of the 845G chipset's AGP interface. Nestle an AGP card into the board's AGP slot, and the built-in graphics are automatically disabled; they give back the main memory and memory bandwidth they'd normally occupy, and this 845G board acts for all the world like an 845E.

If you do want to make use of the built-in graphics, you're getting one of the more decent built-in graphics implementations around. Thanks to the Pentium 4's front-side bus and the 845G's DDR memory controller, the graphics situation here is much better than the old Intel 810/815 chipsets and the like. There's just more memory bandwidth to go around, and since the CPU and graphics controller have to share memory, that's a relief.

The 845G graphics controller is curious, because it doesn't ask for any more than 8MB of system memory. Most integrated graphics solutions will partition off quite a bit more memory; the SiS 650 can grab as much as 64MB. Yet with 8MB allocated and only 8MB occupied according to Task Manager, the 845G shows up as a 48MB graphics device.

A 48MB graphics device occupies only 8MB of our system's 512MB total RAM.

No doubt some sort of dynamic memory partitioning or AGP trickery is at work here, but the mechanism is transparent to the end user.

What to watch for in the test results
We have two basic sets of tests for you today. One is essentially a chipset performance comparison between the 845G and the P4 chipset competition from Intel, VIA, and SiS, with the BG7 in a starring role. In these tests, we included the BG7 with a GeForce Ti 4600 card in the AGP slot. Then we pulled out the AGP card and ran the BG7 through our non-3D-graphics tests to see how turning on integrated graphics affects overall system performance.

As always with chipsets, don't expect massive performance differences here. Core logic chipsets generally only affect performance by a few percentage points one way or the other, unless they're exceptionally good or bad.

When we're testing with the AGP card installed, the BG7 ought to perform just like it would if it were based on the Intel 845E chipset. The integrated graphics are turned off, and otherwise, the 845G is basically the same. Here you'll want to see how much of a boost the 533MHz bus gives the 845G/E versus the original 845 chipset. That's something of an open question, because the original 845 had DDR266 memory just like the 845G/E, and the 845's 400MHz bus has more than enough capacity—at least in theory—to access that RAM without bottlenecks. How much extra performance can we get out of a bus speed increase alone?

Once the integrated graphics are in use, memory bandwidth should drop, and so should overall performance. The question is: by how much? How much of a performance drain is the built-in graphics core? With a 533MHz bus, the penalty may not be so severe as with previous chipsets with integrated graphics.

The second set of tests we have take a look at the BG7's integrated graphics compared to the SiS 650 and to an AGP card based on NVIDIA's GeForce2 MX200. We'll find out how good (or maybe how bad) Intel's new graphics core really is.