Return to the CurtPalme.com main site CurtPalme.com Home Theater Forum
A forum with a sense of fun and community for Home Theater enthusiasts!
Products for Sale ] [ FAQ: Hooking it all up ] [ CRT Primer/FAQ ] [ Best/Worst CRT Projectors List ] [ Setup Tips & Manuals ] [ Advanced Procedures ] [ Newsletters ]

 
Forum FAQForum FAQ   SearchSearch   MemberlistMemberlist  Photo AlbumsPhoto Albums  RegisterRegister 
 MembershipClub Membership   ProfileProfile   Private MessagesPrivate Messages   Log inLog in 
Blu-ray disc release list and must-have titles. Buy the latest and best Blu-ray titles to show off in your home theater!


(non professional) VGA card bandwidth evaluation
Goto page Previous  1, 2
 
Post new topic   Reply to topic   Printer-friendly view    CurtPalme.com Forum Index -> Home Theater PCs
View previous topic :: View next topic  
Author Message
cmjohnson



Joined: 03 Apr 2006
Posts: 5180
Location: Buried under G90s


PostLink    Posted: Sun Mar 13, 2016 7:24 pm    Post subject: Reply with quote


        Register to remove this ad. It's free!
Since you're looking at video card performance, let me say here that I'm looking for information about any (assumed older models) of video cards that output higher than 2048x1536 resolution in analog mode.

It doesn't have to be fast enough for full rate video, I just need a card that'll allow me to output super high resolution test patterns beyond QXGA.
Back to top
gjaky



Joined: 05 Jun 2010
Posts: 2650
Location: Budapest, Hungary


PostLink    Posted: Sun Mar 13, 2016 10:17 pm    Post subject: Reply with quote

Well, what you need is the highest RAMDAC value possible. I think on the recent videocards you hardly find an analog output, if yes then it will be some cost efficient low performance DAC. In the past 10 year or so almost all video cards employed 400MHz RAMDAC, but as my test shoved the different cards behave differently. I only can say what I tested, and I found that the GeForce 7/8 series showed the best performance. These card however don't go beyond 2048x1536. I'm not sure but I seem to remember there was som GeForce 750 GTX -or something like that- which I bvelieve had 450MHz RAMDAC.

What I found also the highest speed RAMDAC was -interestingly- implemented on a Barco medical videocard:
https://www.barco.com/en/Products-Solutions/Image-processing/Medical-display-controllers/Dual-head-5MP-display-controller-for-digital-mammography_1.aspx#!specs
As you can see it can handle 550MHz pixelclock, and supports 2560x2048 though only in grayscale..
What I also found is Planar MD8/PCI DOME controller whatever it is, they say it supports 3200x2560@68Hz

_________________
projectors in the past : NEC 6-9PG xtra, Electrohome Marquee 6-7500, NEC XG 1351 LC ( with super modified Electrohome VNB neckboard !!!)
current: VDC Marquee 9500LC
The MOD: VNB-DB
Back to top
View user's photo album (1 photos)
tschaeikaei



Joined: 08 Apr 2013
Posts: 471
Location: Germany/Saarland


PostLink    Posted: Fri Apr 29, 2016 10:54 am    Post subject: Reply with quote

http://www.nvidia.co.uk/docs/IO/90190/GTX-480-470-Web-Datasheet-Final4.pdf
That's what i have laying here, but not mounted in a PC yet.
I think "dual integrated 400MHz RAMDAC" means one 400MHz chip per DVI port.
Hoping it will not be to fuzzy at higher v-frequencies for 3D.
Nice work Gjaky, i will do the same with my card (when i have build a PC around it) and post here.
Regards, Julian

_________________
2 Marquee 8500U 2001 P43 | Barco 801s LC | NEC 9PG
Self-build 15"-LCD Beamer with 400W HRI bulb
small Teufel 5.1 Audio | HTPC | Pioneer HPM 100
Back to top
gjaky



Joined: 05 Jun 2010
Posts: 2650
Location: Budapest, Hungary


PostLink    Posted: Sat Apr 30, 2016 6:52 am    Post subject: Reply with quote

Thanks,
Yes that card is supposed to have nice analog bandwidth. In fact all later generation (in the past 10 years) videocards will bring decent analog performance.
I also have a few videocards to test, but as it seems the difference between the different cards is usually marginal, at least as I see it on my oscilloscope, which in my case is surely the bottleneck in this measurement.

_________________
projectors in the past : NEC 6-9PG xtra, Electrohome Marquee 6-7500, NEC XG 1351 LC ( with super modified Electrohome VNB neckboard !!!)
current: VDC Marquee 9500LC
The MOD: VNB-DB
Back to top
View user's photo album (1 photos)
tschaeikaei



Joined: 08 Apr 2013
Posts: 471
Location: Germany/Saarland


PostLink    Posted: Sat Apr 30, 2016 1:09 pm    Post subject: Reply with quote

I have a 500MHz scope, HP 54540A, so this should be no problem.
If only i had that PC build yet... Lazy me Wink

Regards, Julian

_________________
2 Marquee 8500U 2001 P43 | Barco 801s LC | NEC 9PG
Self-build 15"-LCD Beamer with 400W HRI bulb
small Teufel 5.1 Audio | HTPC | Pioneer HPM 100
Back to top
gjaky



Joined: 05 Jun 2010
Posts: 2650
Location: Budapest, Hungary


PostLink    Posted: Sat Apr 30, 2016 1:19 pm    Post subject: Reply with quote

That is a nice instrument, I could use one of them too Very Happy
_________________
projectors in the past : NEC 6-9PG xtra, Electrohome Marquee 6-7500, NEC XG 1351 LC ( with super modified Electrohome VNB neckboard !!!)
current: VDC Marquee 9500LC
The MOD: VNB-DB
Back to top
View user's photo album (1 photos)
gjaky



Joined: 05 Jun 2010
Posts: 2650
Location: Budapest, Hungary


PostLink    Posted: Sat Jun 04, 2016 3:12 pm    Post subject: Reply with quote

A 18USD Chinese HDMI to VGA converter:

The output was awfully filtered as it came, it could not even resolve 800x600 60Hz according to the oscilloscope, moreover one of the output termination resistor was a wrong value, so the output levels did not even match.
But after removing the filter network and correcting the termination it revealed that the output rise time I could measure is around 1.6ns, which would equal to ~375MHz analog bandwidth, that is quite good, with adding a filter of course would affect this speed, but the raw power is there for sure. It drived my 3m long RGBHV cable with ease.
There is only one video IC there an EP94Z1E.
Despite the specs say it only supports 165MHz pixel clock, but my short test showed it even put out 1080P 96Hz (~250MHz pixel clock)!



chinese_hdmi.jpg
 Description:
 Filesize:  45.96 KB
 Viewed:  3497 Time(s)

chinese_hdmi.jpg



_________________
projectors in the past : NEC 6-9PG xtra, Electrohome Marquee 6-7500, NEC XG 1351 LC ( with super modified Electrohome VNB neckboard !!!)
current: VDC Marquee 9500LC
The MOD: VNB-DB
Back to top
View user's photo album (1 photos)
Display posts from previous:   
Post new topic   Reply to topic   Printer-friendly view    CurtPalme.com Forum Index -> Home Theater PCs All times are GMT
Goto page Previous  1, 2
Page 2 of 2
Jump to:  
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum
You cannot attach files in this forum
You can download files in this forum