[gtidriver]

I'm running a 4830 card to a 40" Bravia LCD tv. The mobo is 8300-based, I've used the onboard gpu without the issues described now - so it's definitely related to the ATI card, but I prefer the peformance of the ATI. For background, using the VGA-in on the TV results in a resolution of 1360x768, using DVI->HDMI allows up to 1920x1080.


The problem is that when set to 1360x768 the scaling seems correct but the colours are a bit dull. Using in-the-box Win7 drivers shows a "recommended" res of 1360x768. However, I want to use 1080p. I can select this, but then I get two problems: firstly I cannot adjust the scaling to fit the monitor (I get a black "border" of almost an inch around the entire screen) and secondly the fonts have an odd "shadow" effect (cleartype isn't the culprit). I can force the scaling if I install drivers from ATI rather than MS, but the "shadow" remains (even if I disable de-noise and so on). I've also tried adjusting the TV settings, but they only allow "full pixel" (needed for nVidia) or "normal" (works better with ATI).


So my questions are:


1. Is there a way to adjust scaling with the MS drivers (I'm trying to troubleshoot a different issue and therefore want as "clean" an install as possible for now)?

2. Any way to get rid of the shadow apparent with ATI cards but not nVidia? (for interest, an older X1550 card had the same issue, an 8800GTS was fine...)

 

[jrwalte]

You have this 'shadow' because you are not displaying pixel for pixel. Keep the TV set to full pixel. That sounds like its version of pixel for pixel. Then, you're going to have to install ATI drivers to get the CCC. Open up CCC and go to display. I forget this exactly, but I believe you right-click on the display icon in the lower section and you'll be given an option of 'display properties'. Click this and one of the options will be 'scaling'. Make sure this is at 0.


At this time, your PC will then be sending an exact pixel for pixel 1920 x 1080 signal. If it doesn't fill the screen, then it's a setting in your TV. Try different TV picture modes. Once you do get pixel for pixel, your text/icon quality will greatly improve.


Also, so we can be sure your TV truely does support 1080p over HDMI, what is the model?

 

[gtidriver]

Thanks, yes it definitely supports 1080p over HDMI, both 60 and 24p - KLV-40V400A. Works fine with the mobo 8300 as mentioned and also an older 8800GTS 320Mb card, the problem only happens with ATI cards. I have tried both "full pixel" and "normal" (the only 2 options on the TV). Full pixel tends to "shrink" the screen a bit vs normal when displaying the same image.


In other words, the 8300 seems to overscan a bit, using full pixel then pulls the image down a bit to fit perfectly, no adjustments to scaling required at all and the image is sharp. If I do exactly the same with the ATI card, the image is really shrunk, so I set the TV to "normal" which is better, but results in the approx 1 inch border I referred to. To get it to fill the screen, I then also have to adjust the scaling from 0 to +15%. I've tried various refresh rates too, but whatever I do - 1080 with ATI has a shadow. 1080 with nvidia - absolutely perfect. I'm very confused... Tried different HDMI ports on the TV, same story. Different cables (the 4830 and 8800GTS use DVI-HDMI, the 8300 uses straight HDMI), same issue. So it's definitely ATI-related, I just don't understand why - as noted, even an AGP X1550 card did exactly the same thing.

 

[jrwalte]

According to your manual for that model, it officially supports 1360 x 768 @ 60Hz from a PC signal over HDMI. See page 32. It makes a point to say that if you are using a resolution outside of the chart or a different refresh rate other than 60Hz, it may have problems. This probably explains why Nvidia doesn't have an issue but ATI does.


This is odd, considering the TV does have a resolution of 1920 x 1080. Haven't seen a TV state the PC must be a lower resolution than the native resolution before. It appears to maintain pixel for pixel @ 1920x1080 with ATI you'll need to leave the TV at full pixel and ATI overscan to 0% and let the image stay smaller than the TV (black bars on all sides). Unless you still have the shadow issue, and then I'd try 1360 x 768.

 

[gtidriver]

Interesting point, I hadn't thought to check the manual re the PC-input section since it's going via HDMI, not the PC-input D-SUB (VGA analogue) connector. It is very odd, since I don't see how the TV would have any idea it's a PC connected to HDMI (perhaps HDCP?) or why it would care vs any other device. VGA-input I can undertand. The manual is a little confusing as it refers to "PC input" mode, but as part of the D-SUB input section. However, I've successfully put 1080p/60 and 1080p/24 through HDMI from the PC using both the ATI and nvidia cards, it's just that the scaling with the ATI is more difficult and there is the "shadow" around the fonts.


Ah well, since it's just a HTPC I'm going to try the 8300 for now - at least it's quieter than the 4830's fan and should still cope with blu-ray etc. fine. I'll have to find another home for the 4830 which is a pity since it's otherwise a nice card.