|
Hey guys. This wall-o-text is mostly about electrical and technical stuff about the adapters. So just skip it if you aren't interested in this stuff. I wanted to hide it but this board doesn't have spoiler tags that I found.
This post refers to the DP->VGA adapter shown here: http://www.monoprice.com/products/product.asp?c_id=104&cp_id=10428&cs_id=1042801&p_id=5135&seq=1&format=1#largeimage
Which is identical to many others made by Accell and various ebay vendors note the ones with the unique case, they have identical guts.
Anyways, these adapters have this 640x480 issue, where the monitor is detected as 'fake' in ccc and can't be changed out of it. I asked the Accell people if they had a firmware for it, but no reply yet. Honestly, I'm beginning to think that it's driver related. This is all after the ATI-dp hotfix BIOS btw.
How to fix the 640 issue: You have to power cycle the device, it's the only way I know so far. This involves unplugging/replugging it in, which if you do it enough times.. may break your card's DP socket.
Things I have investigated:
Doesn't work at all for eyefinity: Dell DP to DVI cable that came with a dell NVS card. It does have a chip but CCC detects it as DVI, which means that the chip is a simple level shifter, NOT a native DP converter. (changes the voltage only)
Now before I got this monoprice dealie, I was impatient and wanted to get it going. (before I knew about all these damn issues!) As a lot of you have probably figured out, these adapters are hard to find from brick and mortar stores. However, I did find that Apple makes adapters and they are sold all over the place. So I went to Best Buy and got this for 30 bucks: http://store.apple.com/us/product/MB572Z/A Now this should not be confused with the very expensive apple active DVI adapter with the two cables, this is made for the new macbooks and has VGA output. It is a well made device, as with most apple hardware, very good construction. (inside is what matters) But it has a MiniDP connector which would not do at all, and nobody sells adapters to full size DP locally of course. In the end, I hacked off the cable and soldered a spare DP cable on that I had around. But in testing, I ended up frying it by supplying it with too much voltage. See this is the pitfall of Apple making up the MiniDP standard as they went along, the specification whitesheet said that the voltage was valid from 3.3v to like 16v, but not Apple's little adapter.. it was only made to be used on a macbook. Perhaps I misread it but I thought I comprehended it pretty clearly, I read these kind of data sheets all the time. So after hours of meticulously reverse engineering the pinouts and making my hardwired adapter cable which replaces the old one, I was left with a 30$ junk pcb board.
So then, I caved and ordered the Monoprice adapter. And it had issues as most everyone has experienced. So trying to debug this thing, I desoldered the fuse that provides the 3.3v to the conversion chip via pin 20 from the video card. I then powered the converter with a separate ATX power supply, using the 3.3v line of course. Still does the 640 thing unfortunately. This means the power from the ATI card is ample and the problem lies in the device itself or drivers. (Note this pin 20 'power' I refer to is not related to what the bios fixed, that was DP signaling voltage on the data lines afaik) Btw, the build quality of the MP adapter is horrendous, there were solder balls and bridges from apparent hand soldering of the connections, as well as pitted joints. I guess you can't expect much.
The monoprice adapter exhibits the following behavior:
Any time the resolution is changed, windows or game, eyefinity or not, the adapter goes tits up with a black monitor and CCC says 640x480.
Going from eyefinity to non-eyefinity does the same.
Going from non-eyefinity to eyefinity does the same.
If going to Eyefinity, CCC tries to recreate the group but since it can only do 640 on one of the monitors, it puts all monitors in 640. :cry:
Rebooting up often results in the 640 madness.
Edit: Coming out of power save causes the issue.
I dealt with these issues for a month or two, and they drove me insane. I cannot leave the system in eyefinity mode because then windows GUI becomes useless and hard to manage, and the nView like software ATI provides called HydraVision is severely lacking, it can't even force the start menu to one screen. I got fed up with reaching under my desk so much to reset the stupid adapter, and I got to the point where I decided to get another Apple adapter.
I get the new Apple adapter (same kind as before) and quickly solder my custom cable onto it. I had to modify the end of the cable which plugs into the video card a little because it didn't originally pass pin 20, it was only meant to be a monitor cable, not power a device. I plugged it in, and low and behold, it works great first try. (I am a bit parinoid about frying my new video card, I rigorously checked and rechecked everything before doing this, and I don't recommend anyone do this unless you have been comfortable around electronics for at least a decade, and skilled in SMT work) I'm super happy now because it seems to work and doesn't do the 640 thing! But then I do some tests, switching profiles from normal triple monitor to eyefinity group mode, and it does it. Argh. :x
Symptoms of the Apple adapter:
Going from eyefinity to non-eyefinity causes the issue.
Going from non-eyefinity to eyefinity causes the issue.
Resolution changes don't seem to affect it now.
Rebooting still sometimes results in the issue.
Edit:Coming out of power save is a-ok.
This leads me to come to the following conclusions:
-The monoprice adapter may have crummy firmware which has resolution switching issues. Good luck getting anyone to give a damn about it though. I asked for a firmware file but I doubt I'll get it. And if I do, I'll have to desolder the SPI eeprom and flash it externally.
-The apple adapter, while being of the highest quality that you could possibly find, still has the issues and this is why I believe it is a driver issue. Do note that the 640 issue happened less on 9.12. (Which I read on the ati forums, and then verified it myself)
-The base issue seems to occur with any DP->VGA adapter, regardless of the type of conversion chip inside. The Apple and Monoprice adapters have different conversion chips, but they are both made by ST Microelectronics. Maybe it is an ST issue, who knows for sure. I couldn't find the datasheets for either chip.
How I am coping with these bugs and limitations:
-I use my custom Apple adapter which has less issues. (until I retest and verify the MP adapter has less issues in 10.3 edit: verified.. Apple adapter has less issues, MP goes 640 far more often.)
-I leave the system in Eyefinity mode.
-I rotated all 3 monitors to landscape to make windows more usable in eyefinity mode. (start menu isn't 5 ft long now)
-I use an app called WinSplit Revolution to manage window placements very quickly, it's a godsend. HydraVision is horrible, ATI needs to take a course in application usability. Winsplit is a bit buggy on my 7 x64 machine, but it wasn't made for 64 bit windows and I think the author hardcoded some reg paths, programming nono. It works fine though, errorboxes in the config aside. http://www.winsplit-revolution.com/
-This 640 issue is not limited to VGA adapters, I have read reports of it happening on DVI adapters too. (the expensive ones)
Ideas I may try or possible solutions:
-With a microcontroller like a pic or arduino, I may be able to detect when a res change occurs and power cycle the adapter. I have no idea how to detect a res change though, what pin would be a likely candidate to sniff, or what. In DP, the lanes carry pure data, and other than 3 extra GPIO wires, there isn't anything else. Perhaps the hotplug pin flops, I'd have to scope them while changing resolutions. I may be able to detect the change on a dvi port instead, and have that cause the DP adapter to reset.
-I have to etch a pcb for an SPI eeprom programmer, I may dump the firmware and try to disassemble it, but since the damn datasheet is nearly impossible to get, I don't even know it's host architecture! And this may yield nothing, since I don't think the issue stems from the adapters in the first place.
-Apple released a firmware update for the adapter I think, but I'll have to depackage the update binary and burn it to the eeprom myself, since I don't have a mac with a displayport out of any kind. Doing this successfully is going to be time consuming and difficult, and with my luck my adapter already has the update.
Here are some pics of the hardware for the electronics geeks: http://picasaweb.google.com/electrosthetics/Eyefinity?authkey=Gv1sRgCJKT7vPz3rW3UA#
I gotta say, issues aside, my computer is something like Minority Report now with 3x 1920x1200 monitors. This tech is super cool.
|
Login
FAQ
Search
Members
