What does the Parhelia 512 look like ?

[P5ycho]

Originally posted by moreau




Um, no.

Dr. Moreau

Surely hot air has less density than cold air... causing it to move upwards.

[DukeP]

A smart producer of AGP cards could quite easily put the processor on the other side of the board. PLenty of room there, even if it doens exactely conform to the ATX standard - but neither does the larger than life Geforce 4 boards.


~~DukeP~~

[Greebe]

The chip doesn't need what you've seen in those rather old Aphpa version pics... and most certainly no need for a Zalman.

thermal energy moves equally in all directions. It's only when air passes over a HS (convection cooling) where it rises

[MrGaribaldi]

But won't the cooling on the Parhelia (as any other cards) be convectional? (sp?)

Not to sound rude, but since all vid.cards (unless modded otherwise) are using convectional cooling, why point out other ways of cooling?
Granted what you say is 100% correct, but it seems a bit besides the point, since the discussion is about how the parhelia will be cooled...

As for not needing the heatsink from the alpha, Good

.02$

[Jazzz]

i found some pics over at vr-zone

[mattsteg]

Originally posted by MrGaribaldi
But won't the cooling on the Parhelia (as any other cards) be convectional? (sp?)

Not to sound rude, but since all vid.cards (unless modded otherwise) are using convectional cooling, why point out other ways of cooling?
.02$

The importance of density changes and circulation induced due to heat changes is by far most relevant when the dominant heat transfer mode is natural convection. This is NOT the case inside your computer, and if it is, you likely have heat issues that cannot be solved by orienting a card differently. The amount of flow induced by natural convection is small, especially when compared to the gains which can be had by going to forced convection. It has been confirmed that Parhelia uses forced convection for cooling, and since this is the case, the "heat rises" phenomenon is not really that useful.

[VJ]

dvi-switching...

K6-III:

Switching digital signals should have absolutely no effect on image quality.

Switching analog will have an effect regardless.

Isn't there an analogue signal on some of the dvi's pins ?

If you use a dvi-vga converter, to drive a regular screen, wouldn't the image quality be degraded when using a dvi-switch ?

Jörg

[MrGaribaldi]

Originally posted by mattsteg
It has been confirmed that Parhelia uses forced convection for cooling, and since this is the case, the "heat rises" phenomenon is not really that useful.

Well, both yes & no....

Yes, because the fan will push/pull the air to cool the heatsink/chip..

No, because the allignment of the card will hamper airflow... When the air has been heated and pushed away, it'll have to find a way upwards/away from the card, as not to be reused...

Depending on the effect of the fan, this can be done with little or much problems...

If, on the other hand the chip had been on the top of the card, the "used" air would have much less problems finding ways up- and out-wards afaik... It would depend a bit on the HSF on the cpu, but still...

.02$

[Yannick]

Most computers that I've seen reject air through the ATX power supply and out of the computer at the back. Sometimes there's even an extra fan in front pushing some air inside at the bottom. Which means that the general flow of air goes upwards.

Now, if the Parhelia's fan is like many CPU or GPU's fans, it will pull air from below and reject it on the sides of the heatsink (with plenty of room around the card to get away. That's pretty good in my opinion, since the general airflow is going upwards.

[Yannick]

Originally posted by MrGaribaldi
Not to sound rude, but since all vid.cards (unless modded otherwise) are using convectional cooling, why point out other ways of cooling?

Well it seems to me that many higher-end video cards use fans out of the box. My G400MAX for one. Well OK, that's one that's officially overclocked. But It seems to me that all the latest GeForce based cards use some kind of fan-powered heatsink, sometimes with heatsinks on the DDR chips benifiting from the centrifugal flow of the GPU's fan. (At least, that's what I've seen on a hardware news site that shows photos of almost every new graphics board).

[VJ]

If I'm not mistaken, the original ATX-spec stated that the PSU fan would suck air in, thus cooling the processor .

The current spec:

http://www.formfactors.org/developer/powersupply.htm

more specifically:

http://www.formfactors.org/developer/specs/atx/atx12vPSDGV1.pdf

has changed this, and while the standard is now that the PSU fan should blow air out of the case, the original idea (sucking air in) is still within spec (excerpt from the forementioned pdf-file) :

The ATX Specification offers two options for venting between the power supply and the system interior:
· The venting shown in Figure 4 provides the most effective channeled airflow for the power supply itself, with little regard for directly cooling any system components. This venting method is nearly always used in conjunction with a fan that exhausts out the rear of the power supply.
· The venting shown in Figure 5 allows designers to more directly couple the power supply airflow to system components such as the processor or motherboard core, potentially cooling all critical components with a single fan. Both the power supply fan location and direction may vary in this case. The trade-off is usually one of reduced system cost versus narrower design applicability.

In the early days, a lot of atx-supplies were actually out of spec, as they blew air out of the case (which turned out to be more efficient).

Jörg

[dneal]

I think the cards are upside down to keep dust collection on hot surfaces to a minimum. Just think how bad a heatsink would get in mom & dad's computer after 3 years of no cleaning

I once cleaned out a Dell tower that was about 3 years old, was like a inch of dust built up. I also cleaned out a XT a few years ago. Was a gaggingly awful situation.

I have no doubt that dust on some of these hot video cards would quickly become a fire hazard. At the least the card would thoroughly overheat.

[Wombat]

I don't mind the cards being upside down. If they weren't, I bet we'd see a lot of cards that threw off all their heat to bake the cards above them.

[Yannick]

Originally posted by dneal
I once cleaned out a Dell tower that was about 3 years old, was like a inch of dust built up. I also cleaned out a XT a few years ago. Was a gaggingly awful situation.

It gets dreadful when someone smokes in the room. (Same thing for CD burners of people that smoke, I was told).


As for the problem of accumulating dust... When you have a Slot1 processor, you'll notice how its fan-powered heatsink puts a nice layer of dust on the video card, exactly behind the MGA-G200 processor.

[Greebe]

Yes it's true that smoking in the room is the worst thing one can do around puters especially with cdrom drives. Friend of mine smokes around his and the cdrom drive died (also horrifically discolored)... he was going to replace, but seeing that he's an EE Tech I suggested cleaning it throughly (ala disassemble and dishwasher it and include JetDry)

A couple of weeks later he got off his lazy arse and did so... worked like a peach.

I have a Fram Auto air filter installed on the air intake of my radiator (system is water cooled for those who don't know) and it works a peach... no dust or anthing for that matter... and for only $5 at Walmart. Like a sore dick you can't beat it