Imaging Resource
Without a doubt, the EOS 20D is an impressively fast camera, all the more so given its 8.2 megapixel imager. (That's a lot of data to sling around that quickly.) Shutter lag is better than that of the earlier 10D, the Digital Rebel, or the Nikon D70, in many cases significantly so. Cycle times are also very impressive, whether in single-shot or continuous mode. Buffer capacity for JPEG images is excellent: Using a low-compressibility color-noise image as the subject, we consistently shot 19 large/fine JPEGs before having to wait for the card to catch up, and at roughly a second per image, post-buffer-fill cycle time was excellent as well.
Shooting in RAW+JPEG mode cuts buffer capacity to 6 frames, regardless of the subject matter or JPEG quality setting, and slows both the post-buffer-fill cycle time and buffer recovery rate as well. - But the cycle time for those first 6 frames is still very good, and you don't have to wait for the buffer to clear entirely before shooting another series.