ATI 3870 -- reference vs. non-reference PCB ??

[Beladi Nasrallah]

ATI HD3870 was released by some Taiwanese and Chinese companies with
non-reference printed circuit board (PCB) design. All of them are
based on the non-reference PCB (developed by the Taiwanese
manufacturer Triplex), e.g.
http://www.unika.com.cn/index.php?o...d=3&task=viewproduct&productid=294&cataid=232

The reference design card is shown e.g. in
http://www.unika.com.cn/index.php?o...d=3&task=viewproduct&productid=290&cataid=232

The non-reference card is shorter (7.4" vs 9" of the reference card),
and it has the fan in the centre of the card, while the reference card
has its fan at the distal end (away from the video connectors). It
also seems to have fewer capacitors. The non-reference card occupies
two PCI slots while the reference card has a one slot width.
Powercolor, Colorful, Apollo, Unika and Triplex itself released the
3870 card based on the non-reference PCB.

Couple of months ago, I had a look at the website of a Chinese
retailer. They sold the "reference" version of the card for around US
$235, and the non-reference version for US$200. Obviously, the non-
reference card is cheaper because it uses a cheaper PCB (was not
bought from ATI) and fewer elements.

So, here is my question: Is the image quality (for which ATI card are
known) is worse in the non-reference version than in the reference
version ? Where should I dig for such an information ? (Searching
Google, MSN and Yahoo for answers did not bring anything up, and I do
not think that the manufacturers will cough up the truth.)

I am asking the question because I am attracted by the short form
factor of the non-reference card, but I would not buying if it has an
inferior image quality.

 

[Guest]

When a card is designed, every component on the card has a
definite purpose. But when the card gets to manufacturing it
goes through a "component reduction" process, where the
company's bean counters decide what components really
aren't necessary, and what components can be replaced by
inferior/cheaper components.

So the bottom line is, if you can find a video card model that
looks true to the card's original design, it's almost certainly
"better", in image quality, durability and probably both.

 

[Paul]

ATI HD3870 was released by some Taiwanese and Chinese companies with
non-reference printed circuit board (PCB) design. All of them are
based on the non-reference PCB (developed by the Taiwanese
manufacturer Triplex), e.g.
http://www.unika.com.cn/index.php?o...d=3&task=viewproduct&productid=294&cataid=232

The reference design card is shown e.g. in
http://www.unika.com.cn/index.php?o...d=3&task=viewproduct&productid=290&cataid=232

The non-reference card is shorter (7.4" vs 9" of the reference card),
and it has the fan in the centre of the card, while the reference card
has its fan at the distal end (away from the video connectors). It
also seems to have fewer capacitors. The non-reference card occupies
two PCI slots while the reference card has a one slot width.
Powercolor, Colorful, Apollo, Unika and Triplex itself released the
3870 card based on the non-reference PCB.

Couple of months ago, I had a look at the website of a Chinese
retailer. They sold the "reference" version of the card for around US
$235, and the non-reference version for US$200. Obviously, the non-
reference card is cheaper because it uses a cheaper PCB (was not
bought from ATI) and fewer elements.

So, here is my question: Is the image quality (for which ATI card are
known) is worse in the non-reference version than in the reference
version ? Where should I dig for such an information ? (Searching
Google, MSN and Yahoo for answers did not bring anything up, and I do
not think that the manufacturers will cough up the truth.)

I am asking the question because I am attracted by the short form
factor of the non-reference card, but I would not buying if it has an
inferior image quality.

The output on a GPU, is digital, up until the DAC. There is a DAC
per gun. Eventually, you get the RGB output, in analog form.

From the RGB signal pads, to the VGA connector, about the only other
elements in the path, would be filter components. A basic VGA might
use a simple inductor on the output. To control emissions, the
filter might be modified, to be a PI filter (two SMT caps plus
the inductor). That shapes the output spectrum (low pass filter).
I've observed some video cards in the past, even had two stage
filters. But I don't see an incentive for the redesigned board,
to go crazy in that area. If you have high resolution photos of
both boards available, you can examine the area near the output
connectors, for three instances of filter components, and make your
comparison there. A change in filter design, could cause slight
fuzziness at super-high analog resolutions. At 1280x1024, the
difference would likely be invisible.

On the digital side of things, the visual quality should be unaffected.
As far as I know, there aren't any additional components on the TMDS signals
feeding the DVI-D side of the DVI connector. One datasheet mentions
series damping resistors for TMDS, for EMI control, but all designs
should stick to the same plan. (No big money saved by removing them.)

So, other than some minor differences possible in the VGA, there
probably isn't too much room for concern on fuzziness of image.

The smaller card may forfeit -

1) Compatibility with defacto standard cooler designs. The
long card may have keepout zones, making room for various
cooling options. You may want to compare the two cards,
to see whether after market cooling is still possible.

2) Power converter design differences. This is where a company
can save a few bucks, by redesigning the power converters.
The card converts 12V, to lower voltages like 1.8V or 1.5V etc.
The GPU consumes many amps, which is why the converter is
multiphase. Theoretical reliability could be affected. More
than one power converter is used, as more than one voltage
is needed.

3) The shorter PCB saves the manufacturer some money. The layer
count of the two PCBs could be different, but I doubt they'd
change that. Sometimes, a minimum layer count is required, due
to the needs in routing the breakout around the GPU. (The GPU has
a lot of contacts on the bottom, and the copper tracks have
to be routed out between them. More layers are added, to yield
more routing channels for the copper tracks.)

Review sites don't have the incentive, to analyze designs at
that level. There have been the odd article, that looked at
output issues (such as the issue with non-compliant DVI
outputs on early DVI cards). But generally, all cards are
treated as if they're equal now. (Just like nobody tests
2D performance of video cards any more. They're all assumed
to be the same.)

HTH,
Paul

 

[First of One]

Couple of months ago, I had a look at the website of a Chinese
retailer. They sold the "reference" version of the card for around US
$235, and the non-reference version for US$200. Obviously, the non-
reference card is cheaper because it uses a cheaper PCB (was not
bought from ATI) and fewer elements.

Not necessarily. And prices from a couple of months ago are no longer
relevant. I can't actually find a Triplex card for sale in North America,
but Newegg sells the Apollo 3870 with the same short PCB and same cooler:
http://www.newegg.com/Product/Product.aspx?Item=N82E16814140087

It is listed at the same $190 price point as the Sapphire 3870 with the
reference PCB:
http://www.newegg.com/Product/Product.aspx?Item=N82E16814102719

So, here is my question: Is the image quality (for which ATI card are
known) is worse in the non-reference version than in the reference
version ?

If you have an LCD connected via digital DVI (like most people do nowadays),
then there would be no difference in image quality. If you have an analog
monitor, then a cheaply-made card with cheap filters will give worse image
quality. However, a mfr can use the reference PCB layout and substitute
cheaper components on there at any time.

Where should I dig for such an information ? (Searching
Google, MSN and Yahoo for answers did not bring anything up, and I do
not think that the manufacturers will cough up the truth.)

Nobody evaluates analog image quality anymore, due to the prevalence of DVI
monitors. The last review I've seen where this is evaluated
semi-scientifically was written in 2001. Basically two reviewers looked at
the monitor output and gave each card a score from 1 to 5:
http://www.anandtech.com/showdoc.aspx?i=1507&p=4

 

[KlausK]

I used a Sapphire Reference 3870 and am using a Sapphire non-ref 3870. I
like the non-ref better. It runs cooler and overclocks much better
(currently running at 850/1200 with a Thermalright HR-03 GT Heatsink + a
92mm Silenx fan; idle temp 35C, full load temp 46C).

 

[Carl]

I am trying to run a reference and non reference 3870 in Crossfire, I have
never had so many crashes before. I think that there must be a problem with
the crossfire driver, if i turn off crossfire, games run ok. Crossfire
enabled, after a short time, the monitor displays a chessboard corruption,
sometimes crash to desktop, sometimes a total lock up. Hope the next driver
update improves things, or one card is going on ebay for a pittance...

 

[First of One]

1. Make sure Catalyst AI is not disabled. This feature is needed for the
driver to automatically select the correct Crossfire operating mode for each
game.

2. For troubleshooting purposes, run the game at 16x AA, which will force
the Crossfire mode from Tiling to SuperAA.

 

[Carl]

Thanks, I'll give it a go!

 

[Carl]

Cat 8.3 seems to have cured most of the problems. The reference card is
referred to as HD3870 in device manager, with the non reference card called
HD3870 series. I tried Crysis on a 24" widescreen, and it ran ok on medium
settings, game default.

 

[Beladi Nasrallah]

If you have an analog
monitor, then a cheaply-made card with cheap filters will give worse image
quality. However, a mfr can use the reference PCB layout and substitute
cheaper components on there at any time.

Thanks, everyone, for your answers. Here I see two non-reference
Radeon HD3870 cards for sale (same PCB). One of them (from Apollo)
has only electrolytic capacitors, and another one (from Colorful) has
only solid state capacitors. The question is, how bad is to have a
video card with electrolytic capacitors ?

I have done reading on the Internet, and it appears that good-quality
electrolytic capacitors have a life span of 12-15 years. They degrade
much quicker if exposed to heat. I imagine that such a card generates
lots of heat... so that the capacitors will always be hot and may die
quickly. How quickly ? I guess 5 years of life would be more than
enough, 1-2 years would be a too short life.

 

[Flasherly]

Thanks, everyone, for your answers. Here I see two non-reference
Radeon HD3870 cards for sale (same PCB). One of them (from Apollo)
has only electrolytic capacitors, and another one (from Colorful) has
only solid state capacitors. The question is, how bad is to have a
video card with electrolytic capacitors ?

I have done reading on the Internet, and it appears that good-quality
electrolytic capacitors have a life span of 12-15 years. They degrade
much quicker if exposed to heat. I imagine that such a card generates
lots of heat... so that the capacitors will always be hot and may die
quickly. How quickly ? I guess 5 years of life would be more than
enough, 1-2 years would be a too short life.

Sapphire used to be the OEM standard for meeting ATI-engineered board
specifications. Not sure how that works since that last few years,
though.

http://www.newegg.com/Product/Product.aspx?Item=N82E16814102723

 

[Beladi Nasrallah]

Sapphire used to be the OEM standard for meeting ATI-engineered board
specifications.  Not sure how that works since that last few years,
though.

http://www.newegg.com/Product/Product.aspx?Item=N82E16814102723

Thanks for your reply, but that was not my question. I am looking at
an HD3870 card, and it has electrolytic capacitors in it. I am
thinking: "Will this card last ? Or, should I be better looking for a
card with solid-state capacitors ?"

Here is what I found. Here is an article about the role of capacitors
in videocard, http://www.dansdata.com/io070.htm (look for an article
in the middle, titled "If it falls off, it isn't necessary"). It says
that capacitors are used to smoothen the voltage spikes in the power
supply line. The card will work without them, but will just be more
susceptible.

Here is another link, http://www.leadtek.com/eng/3d_graphic/overview.asp?lineid=1&pronameid=410
.
It gives you a table with an estimation of life time of electrolytic
aluminium capacitor and aluminium solid capacitor in a video card
Leadtek 9600GT. At a temperature of 85 C, the electrolytic capacitor
has a life time of 8000 hours (the solid state has 20000 hours). This
means that your videocard is good for 2000 days, or 5.5 years of
gaming provided you play 4 hours per day. With a temperature of
operation of 65 C, you get the lifetime 4 times longer. Phew. It seems
that getting a videocard with all electrolytic capacitors is fine.

 

[Paul]

Thanks for your reply, but that was not my question. I am looking at
an HD3870 card, and it has electrolytic capacitors in it. I am
thinking: "Will this card last ? Or, should I be better looking for a
card with solid-state capacitors ?"

Here is what I found. Here is an article about the role of capacitors
in videocard, http://www.dansdata.com/io070.htm (look for an article
in the middle, titled "If it falls off, it isn't necessary"). It says
that capacitors are used to smoothen the voltage spikes in the power
supply line. The card will work without them, but will just be more
susceptible.

Here is another link, http://www.leadtek.com/eng/3d_graphic/overview.asp?lineid=1&pronameid=410
.
It gives you a table with an estimation of life time of electrolytic
aluminium capacitor and aluminium solid capacitor in a video card
Leadtek 9600GT. At a temperature of 85 C, the electrolytic capacitor
has a life time of 8000 hours (the solid state has 20000 hours). This
means that your videocard is good for 2000 days, or 5.5 years of
gaming provided you play 4 hours per day. With a temperature of
operation of 65 C, you get the lifetime 4 times longer. Phew. It seems
that getting a videocard with all electrolytic capacitors is fine.

If you were a real believer in reliability data, I think you'd be
shocked, if you saw the calculated numbers for the GPU itself.
Rather than worrying about the caps, I'd want to make sure my
new video card had a good cooler.

This document is a fairly easy read. It says there are a couple factors
leading to failure. One factor is temperature related, and the
empirical relationship is 10C cap temp reduction, doubles the
lifetime. But after 15 years, the seal material may fail, so
there is a wearout that prevents the cap from lasting forever.
Presumably, you can find similar documents that discuss the
multiple factors that might affect a solid cap. Be wary of
simple minded marketing efforts...

http://www.illinoiscapacitor.com/uploads/papers_application/85560DAA867C4AE2871F2EFA1749A6C7.pdf

Electrolytic caps are fairly well understood, to the point that
people can identify "cheating" in construction, just by looking
at the devices. The rise in failures, due to bad electrolyte
composition, in past years, was a departure from the norm, and
didn't do anything for electrolytic caps reputation. It should be
possible to build designs, where the caps last longer than the
user is willing to continue using the card (due to obsolescence).

So while a solid cap is "nice to have", it might not be the
only thing that is unreliable on the card.

Paul

 

[KlausK]

..
"It gives you a table with an estimation of life time of electrolytic
aluminium capacitor and aluminium solid capacitor in a video card
Leadtek 9600GT. At a temperature of 85 C, the electrolytic capacitor
has a life time of 8000 hours (the solid state has 20000 hours). This
means that your videocard is good for 2000 days, or 5.5 years of
gaming provided you play 4 hours per day. With a temperature of
operation of 65 C, you get the lifetime 4 times longer. Phew. It seems
that getting a videocard with all electrolytic capacitors is fine."

I have a Sapphire non-reference (blue) HD3870. With a Thermalright Heatsink
attached, it never reaches 46C under full load (3D Mark 06) despite that
it's OC'd to 850/1166. Your card will last for a long time.