I recently bought an R9 290 from Sapphire. For some reason it is not going into zerocore mode with my two monitor setup. The GPU runs at 300/1300 (core/VRAM) in idle.
To circumvene this problem and save as much energy as possible I manually underclock it using an MSI afterburner profile. However, afterburner does not let me underclock lower than 500/650, which is still too much power for surfing and office work. Is it save to underclock lower than that? Do you know if I can change some ini files so that Afterburner can clock even lower?
R9 290 on idle draws only 16W, but your problem is multi-monitor setup which on idle rises power consumption up to 51W. Despite that, if you use 2 identical monitors with same timings and resolution, it will lower power consumption, but how much I don't know. See tests for yourself http://www.techpowerup.com/reviews/Sapphire/R9_290X_Tri-X_OC/22.html
Try to check power consumption disconnecting second monitor, then connect again and try to set same resolutions and timings if it posible. Check differences. Let us know numbers ;)
ZeroCore only turns on, when the computer turns the monitor off. The only time it turns the GPU (whilst at the desktop) off is when there is a crossfire setup. Where it turns off all but the primary card.
Lets forget about zerocore. Do you know if its save to further downclock the GPU. I would love to have 150/300 in idle. Do you know how I could modify the sliders in afterburner so that it can set these values?
