# Custom PC build opinions **URL:** \ **Category:** In My Humble Opinion\ **Created:** [December 25, 2012, 4:27am UTC](https://boards.straightdope.com/t/custom-pc-build-opinions/645092 "2012-12-25T04:27:43Z")\ **Posts on this page:** 10\ **Page:** 2
**Author:** ![SenorBeef](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/senorbeef/32/2220_2.png) [@SenorBeef](https://boards.straightdope.com/u/SenorBeef)\ **Post date:** [December 26, 2012, 10:41pm UTC](https://boards.straightdope.com/t/custom-pc-build-opinions/645092/21 "2012-12-26T22:41:35Z")
You guys are essentially right, and people massively overrate their power needs (the people who buy 850+ units are generally crazy), but power supplies supply power along several rails and their total amperage is divided that way. You can run into a situation where the total power output is adequate, but not instantaneously along the rail it’s needed. There’s also a natural degrading of 10-20% of a power supply’s output over the years. So yeah, a good quality 550w PSU is adequate for him, but I’d still rather step it up to 650 for that extra margin. The power that comes in is cleaner and less jittery if it’s at around 50-75% load rather than 75%+. ---
**Author:** ![Gorsnak](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/gorsnak/32/7587_2.png) [@Gorsnak](https://boards.straightdope.com/u/Gorsnak)\ **Post date:** [December 27, 2012, 12:49am UTC](https://boards.straightdope.com/t/custom-pc-build-opinions/645092/22 "2012-12-27T00:49:43Z")
> [@SenorBeef](#): > > You guys are essentially right, and people massively overrate their power needs (the people who buy 850+ units are generally crazy), but power supplies supply power along several rails and their total amperage is divided that way. You can run into a situation where the total power output is adequate, but not instantaneously along the rail it’s needed. There’s also a natural degrading of 10-20% of a power supply’s output over the years. > > So yeah, a good quality 550w PSU is adequate for him, but I’d still rather step it up to 650 for that extra margin. The power that comes in is cleaner and less jittery if it’s at around 50-75% load rather than 75%+. You should have just stopped after saying we were right. 550w is already massively overrating his power needs. It’s people like you that have made it next to impossible to buy good quality reasonably sized power supplies. Why do we always have to fight this fight? Rails, schmails. The [PSU in question](http://www.antec.com/pdf/flyers/BP550PLUS_flyer.pdf) delivers 12v on three rails, each of which can deliver over 250W (with a combined total not to exceed 444W). Any one of those rails could power the whole computer. The OP’s build is going to struggle to draw half the capacity even under peak load conditions. He _might_ be able to go over 50% running simultaneous CPU and GPU benchmark suites while at the same time transferring files between optical drives and hdd’s. He’s not going to come anywhere near 75% capacity, and even if he did, so what? Jitter? Seriously? It’s an Antec. They might not be the most expensive brand out there, but they don’t make crap. I guarantee the jitter doesn’t exceed the ATX spec, and that it will be a complete non-issue unless he’s trying to push the limits on overclocking or something. A good quality **350W** PSU is adequate for him. ---
**Author:** ![SenorBeef](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/senorbeef/32/2220_2.png) [@SenorBeef](https://boards.straightdope.com/u/SenorBeef)\ **Post date:** [December 27, 2012, 1:49am UTC](https://boards.straightdope.com/t/custom-pc-build-opinions/645092/23 "2012-12-27T01:49:57Z")
> [@Gorsnak](#): > > You should have just stopped after saying we were right. Well, except that the rest of your post demonstrates that you don’t really know what you’re talking about. > [@](#): > > 550w is already massively overrating his power needs. It’s people like you that have made it next to impossible to buy good quality reasonably sized power supplies. Why do we always have to fight this fight? Really, people like me recommending a decent 650w unit for another $10-20 are causing the power supply race wars? > [@](#): > > Rails, schmails. The [PSU in question](http://www.antec.com/pdf/flyers/BP550PLUS_flyer.pdf) delivers 12v on three rails, each of which can deliver over 250W (with a combined total not to exceed 444W). Any one of those rails could power the whole computer. And here’s where you don’t know what you’re talking about. First off, saying “delivers 12v on three rails” is irrelevant to the discussion. It wouldn’t matter if it had 1 12v rail. It’s the total amperage across the 12v rail in this case that matters. But that’s only part of hte issue. You’re ignoring the fact that a power supply doesn’t just deliver power alongside its 12v rail. There are devices that require 5v and 3.3v draw too. Now, because wattage is amperage times voltage, these rails deliver less total wattage to the power supply. So some power supply makers oversupply the 12v rail knowing that it will create more impressive overall wattage numbers. You could hypothetically have a 1000w power supply that was incapable of powering a CPU based on the load distribution between rails of the different voltages. So you’re correct in indentifying total TDP of the different components, and yet unaware of those different components aren’t drawing from one big collective rail at the same voltage. Having a power supply whose nominal total power rating meets the TDP requirements of the individual components is not a conclusive way to determine power needs. Additionally, TDP is not an actual theoretical maximum power draw of the components. TDP is rated as a normal/average high load rather than a maximum load, as it’s designed to deal with the needs of the cooling system design rather than the electrical design. A system can very well, and commonly will, exceed the TDP of all the components added up. This is also ignoring the fact that power supplies become less efficient with age, and that power supply problems can be intermittent and hard to diagnose. You can alleviate the risk of all of that by just spending an extra $10-20 on a higher tier power supply, and as part of a $1000+ computer, that’s a trivial addition to the cost. The higher end PSUs often deliver cleaner power, especially at a lower load number, which is nice if you plan to overclock. So yeah, the PSU he has is probably adequate and would work fine, but there’s nothing wrong with spending a little extra to give that little extra bit of headroom and stability. ---
**Author:** ![scr4](https://avatars.discourse-cdn.com/v4/letter/s/59ef9b/32.png) [@scr4](https://boards.straightdope.com/u/scr4)\ **Post date:** [December 27, 2012, 3:23am UTC](https://boards.straightdope.com/t/custom-pc-build-opinions/645092/24 "2012-12-27T03:23:38Z")
> [@SenorBeef](#): > > You can alleviate the risk of all of that by just spending an extra $10-20 on a higher tier power supply, and as part of a $1000+ computer, that’s a trivial addition to the cost. But if you use a larger power supply, you end up with less efficiency, because switching power supplies are more efficient at higher power output levels. That is, a 1000W supply working at 20% load is less efficient than a 500W supply working at 40% load. ---
**Author:** ![SenorBeef](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/senorbeef/32/2220_2.png) [@SenorBeef](https://boards.straightdope.com/u/SenorBeef)\ **Post date:** [December 27, 2012, 4:05am UTC](https://boards.straightdope.com/t/custom-pc-build-opinions/645092/25 "2012-12-27T04:05:56Z")
That’s true, it may cost you 75 cents a year on your electric bill. ---
**Author:** ![Gorsnak](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/gorsnak/32/7587_2.png) [@Gorsnak](https://boards.straightdope.com/u/Gorsnak)\ **Post date:** [December 27, 2012, 4:19am UTC](https://boards.straightdope.com/t/custom-pc-build-opinions/645092/26 "2012-12-27T04:19:04Z")
> [@SenorBeef](#): > > And here’s where you don’t know what you’re talking about. First off, saying “delivers 12v on three rails” is irrelevant to the discussion. It wouldn’t matter if it had 1 12v rail. It’s the total amperage across the 12v rail in this case that matters. But that’s only part of hte issue. You’re ignoring the fact that a power supply doesn’t just deliver power alongside its 12v rail. There are devices that require 5v and 3.3v draw too. Since the ATX rev2 spec, all the big draws are on the 12V rail. I dare you to find any ATX rev2 PSU that has insufficient 5V or 3.3V delivery for any modern computer. A modern PSU might have issues with very old motherboard/cpu combos that require large amounts of 5V, and you won’t be able to power new mobo/cpu combos with very old PSU’s for the opposite reason, but that’s pretty much never going to be the case with current devices outside of contrived circumstances. > [@](#): > > Now, because wattage is amperage times voltage, these rails deliver less total wattage to the power supply. So some power supply makers oversupply the 12v rail knowing that it will create more impressive overall wattage numbers. You could hypothetically have a 1000w power supply that was incapable of powering a CPU based on the load distribution between rails of the different voltages. That’s nice. I know Ohm’s Law too. Can you name any current product from a reputable brand that doesn’t deliver sufficient wattage on the 3.3V and 5V rails? Very high power draw home computers pretty much universally need extra 12V on the PCI-E plugs on the end of the video cards which don’t even have 5V or 3.3V connections. Or I suppose you might have some massive RAID, but that’s not the case here and is primarily 12V draw as well anyways. > [@](#): > > So you’re correct in indentifying total TDP of the different components, and yet unaware of those different components aren’t drawing from one big collective rail at the same voltage. Having a power supply whose nominal total power rating meets the TDP requirements of the individual components is not a conclusive way to determine power needs. > > Additionally, TDP is not an actual theoretical maximum power draw of the components. TDP is rated as a normal/average high load rather than a maximum load, as it’s designed to deal with the needs of the cooling system design rather than the electrical design. A system can very well, and commonly will, exceed the TDP of all the components added up. Have you _ever_ looked at real life power draw of computers? In the absence of dual GPU configurations or those old obscenely high voltage Pentium IV’s, it’s bloody hard to pull more than 400W _at the wall_ under any real life use. 400W at the wall is only 300-350W DC, which is what the rating is for. [Here](http://www.silentpcreview.com/article1245-page1.html) you can see a nice breakdown of actual power draw. The highest wattage testbed they used had a 140W TDP CPU and a 220W TDP GPU. Running Prime95 and Furmark simultaneously, they managed 389W DC draw, or 30W over the combined TDP of the CPU and GPU. That’s more power than you’ll ever pull during actual gaming, because actual games will never max out CPU and GPU simultaneously. One or the other will be a bottleneck. The OP’s configuration under similar conditions would be drawing 250W, which is a whole 45% of the rated output of his PSU. Actual games will likely draw 35-40% of the PSU’s rated output. Non-gaming use will likely draw ~20%. > [@](#): > > This is also ignoring the fact that power supplies become less efficient with age, and that power supply problems can be intermittent and hard to diagnose. You can alleviate the risk of all of that by just spending an extra $10-20 on a higher tier power supply, and as part of a $1000+ computer, that’s a trivial addition to the cost. Yes, losing 10-20% of power capacity on a PSU which will never see a draw over 50% of it’s rated output is something to be very concerned about. I agree that spending extra on good PSU’s is often a wise investment, but I would far sooner sink that extra money into better quality components than extra rated capacity that will never be used. By all means recommend a Seasonic 80+ Gold-rated PSU over the Antec 80+ Bronze if you like. Just don’t pretend that going from 60% headroom to 70% headroom is something worth spending on. > [@](#): > > The higher end PSUs often deliver cleaner power, especially at a lower load number, which is nice if you plan to overclock. > > So yeah, the PSU he has is probably adequate and would work fine, but there’s nothing wrong with spending a little extra to give that little extra bit of headroom and stability. I’d like to see a cite that higher _capacity_ PSUs deliver cleaner power. By all means recommend a higher _quality_ PSU if you like, but your recommendation was only to go from 550W to 650W for additional (and useless) headroom. In general, going to higher _capacity_ will result in poorer quality power delivery, since most PSUs actually perform best at significant load. Many do not hit their advertised efficiency numbers until over 50% load. ---
**Author:** ![Deereman](https://avatars.discourse-cdn.com/v4/letter/d/a3d4f5/32.png) [@Deereman](https://boards.straightdope.com/u/Deereman)\ **Post date:** [January 25, 2013, 6:32pm UTC](https://boards.straightdope.com/t/custom-pc-build-opinions/645092/27 "2013-01-25T18:32:33Z")
The beast has been built and tamed…for the most part. I appreciate all the advice and opinions given. Wasn’t a hard process, though a bit time consuming getting everything in and plugged in. Heck it took me a few days to figure out what cables I missed to get the case fans running. There are a couple hiccups of course. The 3TB drive…well after formatting it, and found that only 2TB is accessible. After looking online, it appears I need to reformat into GPT to get it all. But I can’t figure out how, I can’t get it to list the GPT format again…and I’m pretty sure it did the FIRST time. Any suggestions? And the Blu Ray player…can anyone suggest a Blu Ray playing program. It didn’t come with one, of course. I’ve heard it’s a major pain to get one that works for any period of time ---
**Author:** ![jacobsta811](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/jacobsta811/32/2893_2.png) [@jacobsta811](https://boards.straightdope.com/u/jacobsta811)\ **Post date:** [January 25, 2013, 6:52pm UTC](https://boards.straightdope.com/t/custom-pc-build-opinions/645092/28 "2013-01-25T18:52:45Z")
Re:3tb drive. If you aren’t using it as your OS drive, open up an administrator command prompt (search CMD, right click, choose run as administratory). Type “DISKPART” and hit enter. You’ll be in the windows disk management. Type “LIST DISK” and hit enter. Find the disk you want on the list and type “SELECT DISK #” where # is the number of the disk you want and hit enter. type “CLEAN” and hit enter. This will erase _EVERYTHING_ on the 3TB disk. Type “CONVERT GPT” and hit enter when done. Then you can create partitions and format as normal (see [JW Goer Lich -](http://www.jwgoerlich.us/blogengine/post/2009/11/05/Use-Diskpart-to-Create-and-Format-Partitions.aspx) for instructions in diskpart. If your OS is already on the disk, you need to backup your data somewhere else, and start from scratch. Boot from the windows install disk and one of the options right at the beginning (under “repair” I think), has a command line with access to diskpart and you have to follow the same steps and then reinstall windows. Cybermedia has a decent pay bluray player. VLC media player ([videolan.org](http://videolan.org)) plays blurays just fine but you have to google to figure out how, like DeCSS in the USA it isn’t legal for them to decrypt without a license. ---
**Author:** ![Mdcastle](https://avatars.discourse-cdn.com/v4/letter/m/958977/32.png) [@Mdcastle](https://boards.straightdope.com/u/Mdcastle)\ **Post date:** [January 25, 2013, 6:58pm UTC](https://boards.straightdope.com/t/custom-pc-build-opinions/645092/29 "2013-01-25T18:58:22Z")
> [@Turble](#): > > Looks like a fine system; no nits to pick. > > Since this is your first time – Rule #1 when putting together a computer: If it doesn’t fit, it doesn’t go there. Thank god we’ve moved past AT power supplies, where it if fits it might not go there. Black on Black: fire and flames lack Orange on Red: your PC is now dead. ---
**Author:** ![control-z](https://avatars.discourse-cdn.com/v4/letter/c/eada6e/32.png) [@control-z](https://boards.straightdope.com/u/control-z)\ **Post date:** [January 25, 2013, 7:28pm UTC](https://boards.straightdope.com/t/custom-pc-build-opinions/645092/30 "2013-01-25T19:28:41Z")
Looks fine if you want to spend that sort of money, personally I go with a ~$150 CPU and ~$150 video card. I stay off the cutting edge and get a little less performance and save a lot of money. [Previous page](https://boards.straightdope.com/t/custom-pc-build-opinions/645092.md?page=1)