Probably better for a computer forum, but here goes... - Page 1
Forum section: electronics / general

author: gooseEL34
author_rank: Regular Contributor
timestamp: August 07, 2013, 04:10:31 pm
content: Folks.I belong to this forum because I build vaccuum tube guitar amps and like the willingness of folks to help.Here is a computer problem:1. I have a desktop PC with an odd sized case so replacing a power supply in it is not feasible.2. The Power Supply says it is a 240W supply (sticker on the top of the supply iteself)3. I want to upgrade video cards.4. The video cards nowadays seem to have 300W power supply requirements (listed on box).Anyone know why the video card is requiring such a beefy power supply? I noticed some of the modern vid cards are running cooling fans on them.I am not running any other peripherals on this CPU other than a PCI Wi-fi card. I am not doing any gaming, video editing, etc. Other than word processing, and videos embedded in websites and youtube, I am not running major video.Is a video card THAT much of a draw on a cpu's power supply?ThanksTim

author: MacAttak
author_rank: Unknown
timestamp: August 07, 2013, 04:15:09 pm
content: Quote from: gooseEL34 on August 07, 2013, 04:10:31 pmThen you don't really need a 300W video card.

author: Unknown
author_rank: Unknown
timestamp: August 07, 2013, 04:22:51 pm
content: Ratings of PC power supplies are often inflated for the cheap brands. A '600W' power supply might not even be able to deliver a stable 300W. Without more details, it's impossible to give specific advice. Some video cards draw 100+W when stressed. It also depends on how much your current system is using: is it a < 50 W Intel Atom system or an old Intel Pentium D system with a TDP in excess of 100W for the CPU allone?If it's for word processing and Youtube, then I guess it's a very low end card. In that case my guess is that you will be fine. Anything with a PCIe power connector (does the 240 W power supply even have these?) would probably be too much. You can check the voltages afterwards to see if they're in spec (I think +/- 5% is permitted for most rails). You can also see if the system is stable when stressed.

author: Phaedrus
author_rank: Frequent Contributor
timestamp: August 07, 2013, 04:25:13 pm
content: I'm in the PC PSU industry, so allow me to respond.The 300W requirement is listed because the vast majority of computers come with a 300W or greater power supply--300W is seen as the "minimum". In reality, 300W is quite substantial, capable of powering a very decent low to mid-range system.Graphics card manufacturers pull their PSU numbers from Nvidia. Nvidia bases their power supply recommendations off of worst case scenarios--assuming that you will be using their graphics card with a high-end CPU, lots of drives, and other hardware. If you are not using this type of heavy hardware, the recommended wattage is probably an overestimation.I don't know what graphics card you're using, but most GPUs that have a recommended PSU of 300W, themselves only pull 15W - 40W.I cannot, however, say that your particular graphics card will work in your particular system. I need to know exactly what hardware you have so I know how much power you're drawing. I also need to know what case and power supply you have, so I can tell if the power supply is quality or not, and if it might be overrated (ie, a 150W power supply labeled as a 240W).It's uncommon to see proprietary power supplies in retail cases, but if it's a Dell or HP it's possible. But I think it's more likely that your PSU is a TFX or SFX form factor unit, in which case there are ready retail replacements available for $50-$70 US (prices may be higher internationally).

author: Stonent
author_rank: Super Contributor
timestamp: August 07, 2013, 06:01:46 pm
content: Most of those cards also have a 4 pin line that's on a separate power rail as well.

author: Phaedrus
author_rank: Frequent Contributor
timestamp: August 07, 2013, 06:10:05 pm
content: Quote from: Stonent on August 07, 2013, 06:01:46 pm? Not since the early 2000s. High-end cards for gaming will usually have 6 and/or 8 pin connectors for additional +12V current, but most low-end GPUs can run solely on the power from the PCIe slot.The PCIe slot delivers 6.25A @ +12V, or 75W. So most GPUs that recommend a 300W PSU don't need additional connectors.

author: gooseEL34
author_rank: Regular Contributor
timestamp: August 08, 2013, 08:25:09 pm
content: Thanks guys.Basics...HP DC5750 desktop in small form factor.Running 3 gig of PC-6400 DDR2Main cpu is AMD 64 Athlon X2 3800Using onboard sound and video for now.Only expansion card right now is a 802.11n wireless card.DVD Rom Drive (not a writer)Seagate SATA 80gb HDDThats about it.

author: Phaedrus
author_rank: Frequent Contributor
timestamp: August 08, 2013, 08:39:14 pm
content: It uses this piece of crap?Sorry mate, you're SOL. Also it has a BTX motherboard, so you're pretty much SOL on upgrading to a new case as well. That computer is proprietary and practically proprietary through and through.Protip: don't buy Dell or HP computers if you ever, ever plan on possibly considering upgrading them.

author: smashedProton
author_rank: Frequent Contributor
timestamp: August 08, 2013, 08:40:21 pm
content: Please please please don't run a high end graphics card off of a computer with ddr2. Getting a new mobo using an apu would solve your problems without needing to change case or power supply

author: Phaedrus
author_rank: Frequent Contributor
timestamp: August 08, 2013, 08:42:40 pm
content: Quote from: smashedProton on August 08, 2013, 08:40:21 pmMy computer has DDR2, and I have an HD6950 2GB graphics card.Memory type alone is not enough to make a call on what you can put in a system... Far from it. Core 2 Quad still lives (for now).His problem is that his computer uses the semi-proprietary BTX form factor motherboard instead of the industry standard ATX. BTX isn't *technically* proprietary, but no one used it except Dell and HP, and retail replacement parts are ludicrously expensive. And now even Dell and HP have abandoned the standard, so everything costs 4x what it should. I don't think you can even get an AMD FM1 or FM2 motherboard in a BTX form factor...

author: smashedProton
author_rank: Frequent Contributor
timestamp: August 08, 2013, 09:38:47 pm
content: Yes you can put it in. But it would be a bottleneck

author: ErikTheNorwegian
author_rank: Frequent Contributor
timestamp: August 08, 2013, 10:14:48 pm
content: If you do a littel dumbster diving, the moste of powersupplays in computers can be recyceld.There is no problem to add a second powersupplay just to feed the graphic card.

author: Smokey
author_rank: Super Contributor
timestamp: August 08, 2013, 10:43:48 pm
content: No one ever said the new power supply had to be attached in the exact same place as the old one. Hell, screw it to the outside of the case and run the wires through the old fan hole.

author: smashedProton
author_rank: Frequent Contributor
timestamp: August 09, 2013, 02:04:36 am
content: Great idea! Just make sure to short the green wires between them to make sure they both turn on

author: Psi
author_rank: Super Contributor
timestamp: August 09, 2013, 03:11:26 am
content: Quote from: smashedProton on August 08, 2013, 08:40:21 pmIt must just kill you to think of people using a hacksaw to remove most of the gold fingers off a PCIe x16 card to make it work in a PCIe 1x slot.(can be done to run a crazy large number of monitors off a PC with only 1 or 2 x16 slots )

author: c4757p
author_rank: Super Contributor
timestamp: August 09, 2013, 03:14:06 am
content: Quote from: Psi on August 09, 2013, 03:11:26 amPeople do that....?

author: Psi
author_rank: Super Contributor
timestamp: August 09, 2013, 03:19:27 am
content: Yep, it happens more often than you think.All the PCIe sockets are the same (1x 4x 8x 16x) they just keep adding more pcie "lanes" onto the end of the connector.The PCIe chipset joins together however many lanes are available to provide the higher level interface.So the card still works with less lanes connected, its just got less bandwidth, which isn't usually a problem if you're using the videocards for lots of extra 2D desktop area.Obviously Crysis isn't going to run well on a cutdown videocard

author: c4757p
author_rank: Super Contributor
timestamp: August 09, 2013, 03:22:00 am
content: I see from your edit that it actuallyworks.I didn't think PCIe (and typical PCIe transceivers, especially) would be that flexible...

author: Phaedrus
author_rank: Frequent Contributor
timestamp: August 09, 2013, 05:01:44 am
content: It's more common to see people cut out the end of the PCIe x1 slot to make an x16 card fit. Slight damage to the mobo is preferable to major damage to the graphics card... It's mainly done for GPU compute systems, for Folding@Home or Bitcoin mining.

author: Psi
author_rank: Super Contributor
timestamp: August 09, 2013, 05:04:11 am
content: Yeah, doing it that was is ideal but most of the time there's a capacitor or other component in the path where the card will sit.

author: Phaedrus
author_rank: Frequent Contributor
timestamp: August 09, 2013, 05:09:08 am
content: Capacitors?We don' need no stinkin capacitors!

author: TerraHertz
author_rank: Super Contributor
timestamp: August 10, 2013, 08:14:01 am
content: Quote from: gooseEL34 on August 08, 2013, 08:25:09 pmYou know by using an odd number of DRAM cards you're forcing the memory system to run at half speed?I happen to have a DC5750 (I didn't BUY it!) and so have the manual stored. Quote:QuoteMy one is used in an equipment rack. But it also serves as a media player. And it can't decode videos fast enough to avoid blocky freezes in the video. Doesn't bother me, since I only care about the audio.