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Video cards and vram

Last response: in Graphics & Displays
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January 1, 2012 6:28:33 PM

on my power supply page, I have a section on extreme top of the line video cards

http://www.hardcore-games.tk/wp/psu.php

NVIDIA is fine, they provide most of what I want :D 

Now the AMD pages are far less informative. They do not give power requirements instead they only give the PSU size needed. :( 

The video card table is down 2/3 of the way to the bottom of the PSU page :hello: 

I would like to flesh out that table more if possible :bounce: 

More about : video cards vram

a c 171 U Graphics card
a c 83 ) Power supply
January 1, 2012 6:50:11 PM

Interesting....

Both the 5 and 6 series are "fabbed" on 40nm. You can find the TDP or max power draw by reading a review.

http://www.techpowerup.com/reviews/HIS/Radeon_HD_6970/4...

Here you can see the 8 memory chips.

http://www.techpowerup.com/reviews/HIS/Radeon_HD_6970/2...

Here is where they show the TDP. Modern cards have become hard to verify the stated TDP because they no longer stay fully clocked when using the usual test programs. It used to be AMD/Nvidia would say "250W TDP" and you could fire up Furmark and check that. Now the drivers see Furmark.exe running and they know to not allow the card to get near the TDP.

Because of this the websites start doing their own thing to measure TDP. I mention all this because the stated TDP for the 6970 is either 225 or 250, I don't remember right now. But as you can see in the maximum power chart they hit 287W for the card. This is because they went messing with the power slider in the drivers and this 287W figure is an "overclocked" figure. Stated TDP numbers are always for stock settings.

Quote:
For our power consumption testing AMD's power control system was set to "0" for all tests. Only for Furmark Maximum, we set the slider to "+20".


If you search in yahoo/google for "AMD card name TDP" or "AMD card name review" you should be able to find all the answers you need. Are you looking for a full critic on your page? I see some stuff that shouldn't be there.
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January 1, 2012 7:20:07 PM

thanks for the links, I was able to much better expand the table to be clearer

extreme video cards need a massive PSU and that is the main focus of the page

any comments are welcome
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January 1, 2012 8:57:00 PM

I have a clamp power meter and line splitter and I have speculated I may need to use it to measure the real load on a machine should I get in to video card reviews

my site is focused on games
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a c 171 U Graphics card
a c 83 ) Power supply
January 1, 2012 10:48:50 PM

The English is "off" in several places. (I'm assuming it's not your native language.) For example,

Quote:
Today all that really matters is the 12V capacity. Older voltages are perfunctory, they are present mostly for USB power and integrated peripherals etc."


is rather hard to read. 3.3 and 5V are the same age as 12V so they aren't really older. In addition, modern computers do use the 3.3 and 5V rails. They just aren't used as much as they used to be. For example harddrives use the 12V rail to power the motor that spins the platters, while the PCB is powered by either the 3.3 or 5V rail.

Quote:
The problem is the design was simply to add more power for a single PCI Express x16 slot which is designed to use a maximum of 65W of power.


I'm not sure why they went to 24pins, but I do know the PCIe 16x slot can provide 75W and not 65W.

Quote:
The latest models now offer triple x16 slots to support full bandwidth for a three-way video card rig


They have boards out now that have 4 or even 7 PCIe 16x slots.

Quote:
Clearly the current ATX PSU is grossly inadequate for modern motherboards that have 2 or more PCI Express x16 slots. Its likely a revision will be needed to increase the number of 12V lines. At least 6 more 12V lines are needed the trend to more x16 slots.


(another bad english spot btw.) Possibly because of the bad English, I'm not sure where you're going with this. It sounds like to me that you are suggesting single rail units can't or soon won't work. This of course is nonsense.

Quote:
Modern motherboards continue to use the 4-pin 12V ATX power but some top models may use the EPS 12V which is 8 pins.


"modern" motherboards all use the 8pin. 4pin is only for older boards, or very budget modern boards.

Quote:
Some power supplies use 2 or more circuits. This is done to reduce costs as high current FET devices are very expensive.


This was probably the first thing that my mind had an issue with. First, I hope you realize that nearly all multi rail PSUs on the market today are really single rail units. Or they start as a single rail unit and use OCP circuits to make them into multi rail units. If what you wrote was true then the single rail units would be cheaper to make. Yet the Corsair PSUs which "famously" use only a single rail aren't really any cheaper then their multi rail Antec counterparts. In truth, on the inside there is very little different between a single rail and "multi rail" PSU. If anything the multi rail units can be slightly safer due to lower OCP settings.

Quote:
Load balancing is vital when using a multi circuit power supply.


Not as much as you would think. Any example you can give me I can counter with the PSU in question isn't large enough to power what you want it to. Remember, there is no such thing as "trapped power".

Quote:
There are several divisions with the gold being the highest


Check your graph to the right. What is that Platinum rating?

Then you had your entire "Add it up" section. You show max possible draw of ALL connections, which hardly ever happens. You will never max out your motherboard, CPU, and GPU. Your first example shows needing a 500W PSU for a system with a single two 6pin PCIe GPU. An example of such a card is the 6870. What is the measured system draw for a system using such a card?

http://www.guru3d.com/article/radeon-hd-6850-6870-revie...

Quote:
Advertised TDP = 150W
System in IDLE = 173W
System Wattage with GPU in FULL Stress = 295W
Difference (GPU load) = 122 W
Add average IDLE wattage ~ 19W
Subjective measured GPU power consumption = ~ 141 Watts


You would actually only need a PSU that can output ~300W. 60% of your 500W figure. The rest of that section has the same error. I would probably just drop it, and use some real world examples with the data you provide farther down with AMD and Nvidia cards.

Speaking of which I would keep that section, but drop the number of memory chips column. It doesn't really matter if a card has 8 chips or 16. The measured TDP of the card is whats important. Finally....

Quote:
Looking at power supplies, the most desirable feature is a single 12V circuit with adequate capacity. Careful checking for a suitable PCI Express connector set is vital for gaming grade video cards. Modular cables are desirable but expensive.


I still haven't heard a good reason why single rail is best. More so at the highest powered units. Even Jonnyguru doesn't like them when you get to the 80A and above units. As he put it in one reviews, that's near welding power, and if you have a short in your system you can kiss that part goodbye. Whereas if you had a multi rail PSU that has a cap of 20A per rail you won't fry anything.

Edited for spelling.
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January 1, 2012 11:08:07 PM

thanks

in my add-it up, its intentionally that way given how many indulge in overclocking

better safer to have adequate PSU when loaded playing Metro 2033 for a few hours
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