TV-Out Connection and Adjustment for GeForce4Ti and GeForce4MX (GeForce2MX) Video Cards with TwinView (nView)

Development of the TwinView (nView) technology on the NVIDIA video cards.

The GeForce2MX video card born several years ago was a revolution in the NVIDIA’s line. Apart from conventional 3D acceleration technologies (where the GeForce2MX, being a lite version of the GeForce2GTS, didn’t shine), the GeForce2MX was the only NVIDIA’s card that supported a unique technology of TwinView.

So, what is the TwinView technology?

The GeForce2MX chip contains two separate and independent video tracks, CRTCs (Cathode Ray Tube Controller), one transferring data to the integrated RAMDAC (Random Access Memory Digital to Analog Converter) and the other to the external DAC (a TV encoder is used as such in the video card supporting TV-Out).

Thanks to such architecture independent signals can be formed on both outputs of the GeForce2MX video card equipped with TV-Out. For example, a first monitor can display an image in 1280×960 at 85Hz and a second one (or a TV screen) can give a picture in 800×600 at 50Hz. At that time such talents were typical of only the Matrox G400 DualHead video card.

For about two years the GeForce2MX (and its clones GeForce2MX200 and GeForce2MX400) was the only card in the NVIDIA’s line with the TwinView support – neither its elder sibling GeForce2GTS with its clones nor the modern GeForce3 didn’t know the TwinView. During that time the competitors of NVIDIA released a great deal of video cards with independent video tracks – Matrox G450 DualHead and Matrox G550 DualHead with a second RAMDAC, dual-head (HydraVision) RADEON VE video cards and then much more powerful RADEON 7500 and finally RADEON 8500 that came from the strongest rival – ATI Technologies.

However, the new GeForce4 line regains the NVIDIA’s share on the market of dual-head solutions: both new chips – the junior GeForce4MX (GeForce4MX420, GeForce4MX440 and GeForce4MX460) and senior GeForce4ti (GeForce4ti4200, GeForce4ti4400 and GeForce4ti4600) do support the TwinView (or, rather, its variation – nView).

Organization of TV-Out in video cards with TwinView (nView).

Let’s see how TV-Out works in the GeForce2MX, GeForce4MX and GeForce4ti families:

  • On all NVIDIA cards with ViVo (Video-In/Video-Out) – GeForce2MX, GeForce4MX and GeForce4ti, the ViVo is supported by the Philips 7108 video processor;
  • On all GeForce4MX cards without ViVo the TV-Out is controlled by a TV-encoder integrated into the video chip;
  • On all GeForce4MX cards supporting Dual VGA an integrated Encoder provides support for a second monitor and a TV-Out is supported by an external processor, most often by a Philips’ chip;
  • In most GeForce4ti cards and some GeForce2MX card a TV-Out is supported by a Conexant TV-encoder (as a rule it is BT868 / 869 or CX25870 / 25871);
  • On most GeForce2MX cards a TV-Out is supported by the ChronTel CH-700x TV-encoder (as a rule, it is CH-7007 or CH-7008).
  • There are a lot of cards equipped with Philips 7102 and 7104 processors; the latter are based on the Philips 7102 and support 1024×768, they differ from the Philips 7108 in a lacking Video-In.

In spite of a big difference in 3D performance the GeForce2MX, GeForce4MX and GeForce4ti are very similar when the TV-out is concerned; and while the GeForce4MX has an integrated TV-Out in the card without ViVo, the GeForce4ti and GeForce2MX have identical TV-Out’s! There is much more difference in organization of TV-Out between video cards of the same family with different TV-encoders than between video cards of different families but with the same TV-Out or ViVo chips. For example, from the standpoint of TV-Out, the GeForce2MX400 with ViVo Philips 7108 is much closer to the GeForce4ti4600 with the same ViVo Philips 7108 than to the GeForce2MX400 with TV-Out Chrontel7008!

That is why the further examination will involve simultaneously GeForce2MX/MX200/MX400, GeForce4MX420/MX440/MX460 and GeForce4ti4200/4400/4600 video cards; peculiarities of different TV-encoder TV-Out will be highlighted.

TV connection

There are not many video cards with TV-Out which have a standard TV composite (RCA, Cinch) connector, – the most models have only an S-Video connector, or sometimes a 6-7 pin connector, similar to PS/2. At the same time most TV sets have only RCA or SCART connectors. So, how should we connect a video card and a TV set if they have different connectors?

In the GF4Ti and GF4MX cards a standard 4-pin S-Video connector is replaced with an S-Video 7-pin one.

Specification of connectors

Pin Name Function
1 GND Ground (Y)
2 GND Ground (Signal), for composite signal
3 Signal Composite signal
4 GND Ground (C)
5 C Color (Chrominance)
6 Not connected
7 Y Intensity (Luminance)

A composite signal can be applied to connectors 5 and 7, but most manufacturers ignore it. But the soldering scheme is usually the same as for a 4-pin connector, in spite of additional pins. Instead of a 7-pin connector you can use a 4-pin one with a removed plastic guide.

For the GF4MX based cards with a built-in chip the adapter looks the same as the one for video cards with the Bt 869 chip.

Choosing a driver

The hardware support is not enough for a correct operation of the TwinView, – you must choose an appropriate driver for your video card which knows the TwinView technology, and adjust it correctly. In this review we will tell you how to choose a proper driver, adjust its settings so that it could use the simplest and most effective way in playing full-screen VideoCD, DVD and Mpeg4 on TV.

It’s not easy to choose a Detonator driver optimal both for TV-Out and 3D functions. Unfortunately, TV-Out is not paid due attention to in various reviews of video cards, though realization of TV-Out can differ much even within the same series of drivers.

The TwinView support first appeared in the drivers of the Detonator 6.xx series, – first it was very weak but in the following versions it grew stronger.

Note: We do not touch upon peculiarities of the drivers regarding quality and speed in 3D in Direct3D and OpenGL applications as it was dealt much with in various reviews. 

The first best driver version for GeForce2MX cards with TV-Out Chrontel and Conexant (only from the TV-Out’s standpoint) was Detonator 7.58-WHQL. In the 12.xx series 12.41-WHQL and 12.90 were also quite successful. In the Detonator 21.xx series the 21.85 driver was the best for GeForce2MX cards with TV-Out Chrontel – the later drivers had some problems with TV-Out (a flicker filter didn’t  work, some settings couldn’t be accessed), but it doesn’t suit for GeForce2MX with TV-Out Conexant, and such cards should be coupled with 12.90 or a Detonator’s driver meant for the GeForce4ti with the same TV-Out chip from the 27.xx-29.xx series. The GeForce2MX cards with ViVo Philips 710x had some problems with tuning up of TV-Out exactly in the Detonator drivers of 7.xx and 1x.xx series (some settings do not work, as well as correction of image position on TV screen), but in the 27.xx and in particular 27.30 and 27.42, TV-Out runs much smoother.

One mustn’t use Detonator drivers older than 27.xx for GeForce4MX and GeForce4ti video cards as they don’t know about such cards. But the GeForce4MX cards with some VideoBIOS version coupled with certain Detonator drivers from the 28.xx and 29.xx series do not “see” TV-Out and, thus, can’t display an image on TV. Some other VideoBIOS version can lack such problems, and TV-Out can work flawlessly. The improved BIOS for the MX440 with an internal TV-encoder can be taken here. By the way, GeForce2MX and GeForce4ti cards can also have troubles with some Detonator versions of the 28.xx and 29.xx series used with certain VideoBIOS versions. So, if you have installed a new Detonator version and your video card doesn’t work with TV-Out anymore (while it worked nicely on another computer) try another Detonator. You can return the driver that worked before the upgrade and if it’s ok look for a new version with a working TV-Out or flash in another VideoBIOS (newer or older). You can do the same thing if your video card can see TV-Out but not all TwinView settings are available (nView). Unfortunately, we don’t have a complete base of compatible versions of VideoBIOS and Detonator drivers.

Note: When we published the article NVIDIA released a new official driver for WindowsXP – 40.41, and a little later we got a leaked version for all operating systems Windows98/ME and Windows2k/XP – Detonator 40.52. 
The first impression is rather good – TV-Out quality is good including the old GeForcexMX (it even seems to be the best after 21.85). 
At the same time the driver is still raw – its settings are often set to default automatically when we try to get in :-( . But there is a wonderful program which allows adjusting the Detonator to your liking (including many hidden settings – RivaTuner).

The complete base of the Detonator drivers can be found at NVWorld – Detonator reference drivers from NVIDIA.

Adjustment of the Detonator driver

The Detonator drivers of the 7.xx-29.xx series have a similar structure of settings relating to TV-Out and TwinView (starting from Detonator 27.xx called nView), though the structure for other settings can differ noticeably, and in the latest version 40.xx the panel of settings has undergone considerable changes.

The further examination is carried out with the Detonator 21.85 on the GeForce2MX card with TV-Out ChronTel7008, with Detonator 28.32 on the GeForce4MX card with an internal TV-Out and with the new Detonator 40.52 on the GeForce2MX card with TV-Out ChronTel7008 under the Windows98SE, and with the Detonator 40.41 on the GeForce4ti4200 card with ViVo Philips7108 under the WindowsXP.

TwinView (nView) supports two modes:


  • Extend: a picture on TV is an extension of a picture on monitor
  • Clone which is actually TwinView itself (nView): a picture on TV is a copy of that on monitor (with some reservations).