Review: Geforce 8400GS pitted against 8500GT

Nvidia allowed some selected partners to produce and sell Geforce 8400GS cards despite the fact that they were originally planed for OEM's only. Zotac showed its versions of Geforce 8400GS on Computex, and from June 9 the cards can be found in retail. The suggested prices for Zotac cards are 59USD/€55 or $69USD/€59 for passively cooled card, but we hope that prices will go down a bit very soon.

The more interesting card is the passively cooled version, which allows the transfer of sound over DVI port, and that's the one we have on test today. The card's full name is Zotac GeForce 8400GS 256MB GDDR2 TC V/D/VO, and you can also find it under the code name ZT-84SEG2P-HSL. We will go back to audio and HDMI a bit later, now lets take a look at why Geforce 8400GS is the cheapest DirectX 10 card on the market.



Geforce 8400GS is based on the G86 GPU, the same one that is used on Geforce 8500GT cards. Core clock is the same, 450MHz, although our Zotac 8400GS works at 459MHz. We mentioned that Zotac has two versions of 8400GS cards, the passively cooled which we have on in our lab today, and another one, low profile card cooled by a small fan.

Memory clocks are the same on both Zotac 8400GS cards, 800MHz, the same clock found on reference 8500GT cards. The fan cooled card doesn't feature sound over DVI so you don't get the HDMI adapter in the box.

Now lets take a look at the most important thing that makes Geforce 8400GS so cheap and so behind its older brother Geforce 8500GT. Of course we are talking about the crippled memory interface, 64bit on this card compared to a 128bit bus on a Geforce 8500GT.

The end result is 6.4GB/s of memory bandwidth versus 12.8GB/s on the 8500GT. Luckily, the card has 256MB of memory, and uses Hynix brand chips at 400MHz. Two memory modules are located at the front of the card, or should we say 128 MBs, while the other 128MB are resting on the back of the card.



The following details are identical to the Geforce 8500GT: 16 Stream processors, 8 Texture Filtering units, 8 Texture Addressing units, and 4 ROP's. Shaders are clocked at 900MHz.

The card is DirectX 10 compliant, and Shader Model 4.0 is supported. Other features are : high dynamic-range (HDR) lighting and the second generation Nvidia PureVideo, called PureVideo HD VP2.

Geforce 8400GS is intended for a Vista user who doesn't want integrated graphics but wants decent video performance and HD-DVD and Blu-ray capability in HDTV 1080p quality. For all those lucky guys who have HDMI TV's, Zotac supplied DVI to HDMI adapters. You can fully use that adapter since it is capable of transferring digital video and audio signal over a DVI connector, and over that HDMI cable to your HDMI capable TV.





The credits for all this go to the little SPDIF connector on the card to which you just have to connect a supplied digital audio cable that is bundled with the card. The SPDIF connector can be found in upper part of the card, next to the heatsink. Unfortunately, because of a malfunction on our test monitor, we couldn't check out the quality of sound, for which Zotac guarantees noiseless quality. Beside the Single-Link DVI out, you can also find VGA and HDTV-Out.




The box is average in size, and beside the Zotac 8400GS card you get a CD with drivers, DVI to HDMI adapter (with sound), SPDIF cable (only the passively cooled one) and S-Video/Composite adapter.

Testbed

Motherboard:
Nforce 680i EVGA board (Provided by EVGA)
 
CPU:
Intel Core 2 Duo 6800 Extreme edition (Provided by Intel)

CPU Cooler:
Akasa EVO AK 922 Blue Athlon 64/X2/FX cooler and Intel CPU's (Akasa)

Memory:
OCZ Reaper PC2-8500 1066MHz 5-5-5-15  (Provided by OCZ)
CL5-5-5-15-CR2T at 2.3V

Graphics card:

Zotac Geforce 8400GS (Provided by Zotac) 

Zotac Geforce 8500GT (Provided by Zotac) 

Asus EN8600GT (Provided by Asus)

PSU:
OCZ GameXStream 700W (Provided by OCZ)

Hard drive:
Seagate Barracuda 7200.9 500GB SATA (Provided by Seagate)

Testing and 3DMarks

Geforce 8400GS is currently the cheapest DirectX 10 card. The ATI HD 2400PRO might end up cheaper, but final price is not yet confirmed. Geforce 8400GS will have to fight that card in the low-end part of market. First results show that ATI is slower, but we will leave our conclusion to when HD 2400PRO comes out. Cheaper usually also means slower, and today we will see how slower the 8400GS really is when compared to a Geforce 8500GT.

Because of the already mentioned technical difficulties with our test monitor we couldn't do the tests on quality of multimedia content. This card is the one of the rare that can transfer both video and digital audio signal over DVI port. So you can get the entire multimedia content to your TV without additional audio cables.

In our standard test we have 3DMarks, while the game testing is done mostly without filters like Anisotropic Filter and Antialiasing. Geforce 8400GS is meant for multimedia and not gaming, but in spite of that you can play games, naturally on lower resolutions and with minimal settings.

3DMarks

In 3DMark 03 the card scores almost 6000 points, but it is still behind 8500GT by 2337 marks. The cards lack of power, caused by its 64bit memory interface, is mostly notable in Single Texturing and Pixel Shader 2.0 test.

All Geforce 8500 and 8600 cards have 128bit memory interface. Geforce 8500GT uses GDDR2, just like Geforce 8400GS, while Geforce 8600 cards come with GDDR3 memory. Geforce 8500GT is 39 per cent faster then Geforce 8400GS.

Geforce 8400GS did 3501 marks in 3DMark 05 test, which is 1224 points or 35 per cent lower then Geforce 8500GT. Zotac 8500GT, with core that is clocked at 700MHz, is 2624 marks or 75 per cent faster then Geforce 8400GS. Weakness of the test card is still shown in Single Texturing and Vertex Shader simple/complex test, and the main cause of all this, if we assumed correctly, is the 64 bit memory interface.