further to the earlier post on "amp glow", here is a composite image showing small segments of a 694 dark frame and a 1600 dark frame. Both were taken at -15, 300s and both have had bias subtracted. The 1600 was run at gain 100 and bias 21. The two images have been stretched so that the total image dynamic range corresponds to 20 electrons - ie we are comparing apples with apples and are looking right down in the noise.
http://astrob.in/full/253351/0/?real=&mod=None
Even though the 694 is a very low noise CCD, it displays a lot more read noise that the 1600 - as expected from the specs. One of the "amp glow" regions of the 1600 is shown - but even that is no more noisy than the average of the 694. The amp glow region incorporates some dark current offset, which can be calibrated out. I have done that on one of the darks and the resulting image is very low noise, with no obvious sign of too much excess noise from the glow - however, much of the read noise in the calibrated dark is clipped at 0 electrons (there is no dark current pedestal to keep it from going negative), so the calibrated dark is not visually comparable to the other two images - to avoid confusion have not posted it.
In summary, the 1600 has lower noise than the 694 over most of the chip. With dark calibration it has lower noise over the whole chip. Regards Ray