Basic guide for the right power supply

[j1n M@tt]

Got a Zeb. PRO-550W from our dealer for testing yesterday Hav to see hw gud the PRO series performs in real-world tests apart from their great specs on paper....btw this is heavier than any 500-600W PSUs I hav ever seen!!! The built quality seems the best so far. Will post soon hw it performs...

[The Sorcerer]

Google and download occt. Run 3 hour cpu testing. After the test is concluded it will give you a graph screenshot of +12v and +3.3v rail during the test. Its best if the system is on default clocks as of now. I will appreciate if you can put the screenshot of that graph over here as well.

[mrsam1999]

I recently bought an i7 rig (920, 3 gb ddr3 1333mhz, seagate 320 gb hdd, lg dvd writer, xfx 9800 gtx+) with this zebronics realwatts pro 600 psu. Now my video card requires 2 6 pin connectors (actually this is 65nm overclocked 9800gtx). But then, i am having to disable HT and also 2 cores of the i7 or else in full fledged gaming, the system is hanging within 2 minutes. I am not overclocking anything. Is the psu low for my config ?

[The Sorcerer]

*facepalm*
i7's average TDP itself is 130w. Its only now that certain zebronics pro versions are good btu that also for systems which demands pretty average power. You will need a power supply which has low voltage ripple and high efficiency for a high performance system. Its obvious- you will need a good power supply.
Here the problem arrives. If zebronics realwatts is replaced with a better psu, the old psu might have already done some damage. So 1st thing first get a better a better psu ASAP- something like tx650. Then you will have to stress test it and see if other components are working properly or not. If they are working- consider yourself lucky. If they are not- be prepared to get them replaced.
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Posted again:
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*facepalm*
i7's average TDP itself is 130w. Its only now that certain zebronics pro versions are good btu that also for systems which demands pretty average power. You will need a power supply which has low voltage ripple and high efficiency for a high performance system. Its obvious- you will need a good power supply.
Here the problem arrives. If zebronics realwatts is replaced with a better psu, the old psu might have already done some damage. So 1st thing first get a better a better psu ASAP- something like tx650. Then you will have to stress test it and see if other components are working properly or not. If they are working- consider yourself lucky. If they are not- be prepared to get them replaced.

[mrsam1999]

Actually with this zebronics psu, i can play all latest games at highest settings no problem. Can u specify what stress test program i should run to test for damage ?

[The Sorcerer]

^^ Are you sure you wanna do that? Dont blame me if stress test damages your system . I rather not take chances and prefer to put 1000 buck more for the sake of being hassle free. I dont have time to give things for replacement and the hassle at times is just not worth it:
Use prime 95 for single core, latest orthos and occt for dual/quad proccies. For checking the system's stability, run the tests for 4-5 hours. But if you are checking overclock stability, you will have to tun orthos 10 hour blend test to make sure its 24/7 stable. Not that I am saying 5 hours run is not enough .

[anoopingenius]

Hi,
I have a 3yr old system with the following configuration:
AMD Athlon 64 3200+
Asus A8Ne Motherboard
2x1GB DDR RAM
XFX 8600GT XXX Ed.
2 SATA HDDs

All these were powered by a Zeberonics 400W PSU and worked fine until yesterday when the PSU went bust (or so I think). After a lot of googling and reading a lot of posts by The Sorcerer and others, I have come to the conclusion that the system was underpowered big time.

I figured that the 12v rail was only providing 9A. (The system originally came with a 6600Le Gfx card, 1 GB RAM n 1 HDD)

Even after the upgrade to 8600GT the system did work fine for 3-4 months. So I cant figure out how the whole thing worked with just 9A. I have found that the 8600GT itself would require 18A min.

Now for the new PSU (hoping all the components are still intact). I was planning to pick up the VIP 500W silver but it is not available anywhere. The CM 390, 460 both have 18A 12v connectors. My Motherboard, If I have got it right has only one 24 pin EATX and one 4 pin ATX12v inputs. So how do I make use of dual 12v connectors on these PSUs (each of which is limited to 12A)?

So is my choice limited to PSUs like the Corsair cx400 which provides 30A on a single rail?

[The Sorcerer]

You have antec EA 430w. There's also coolermaster real power 460w as well. See I made the guide so that people can identify a good power supply for their system, so its not necessary that the recommendations that I made are the best.

[anoopingenius]

If I need atleast 18A for the Graphics card (the xxx edition is factory overclocked, so it could require more), how much more would I require to power the rest? i.e. What else is powered by 12v?

I don't think I have understood this 12v1, 12v2 concept correctly. There is only one 24 pin connector and one 4+4 pin connector in all PSUs. So how does this dual mode (12v1, 12v2) work? I thought there would be 2x 24 pin connectors and corresponding inputs on the motherboard.

I am not just going by your recommendations of PSUs but by the power req of my system. It so happens that your recommendations would suit me fine, if I can only figure out the concept of this dual mode 12v power.

[mrsam1999]

A few days back i benchmarked my rig with everest. I had only 2 cores enabled, turbo and qpi power management enabled too. The tests ran ok, but then, when i started 'painkiller' the game, my pc immediately restarted. I then disabled qpi power management, and things were allright. Now i have disabled turbo mode but enabled all 4 cores and my system is running fine. I have also disabled EIST but kept c0 and c1E states enabled because i think my system is having problems managing voltage and speed to the cpu and chipset. So its better to not let cpu speed get up or down..make it stay put @ stock 2.66 ghz speeds. I am thinking should i select cpu idle state to 'high performance' ? so that it runs at all times in a fixed speed and stepping ?

I dare not run anymore benchmarkers like prime 95 and stuff.

[anoopingenius]

I think I've figured the 12v concept out (correct me if I'm wrong). There are two different 12v lines/rails (limited to 18A by the ATX12v 2.2 std.) feeding the 24 pin connector. So the connector is always one.

So the CM Extreme power plus 390W should suffice with 18A+16A 12V lines as I think in terms of wattage 390 is sufficient to power my system.

[The Sorcerer]

^^ Yes. Keeping this rig in mind, it will suffice.

[The Sorcerer]

A few days back i benchmarked my rig with everest. I had only 2 cores enabled, turbo and qpi power management enabled too. The tests ran ok, but then, when i started 'painkiller' the game, my pc immediately restarted. I then disabled qpi power management, and things were allright. Now i have disabled turbo mode but enabled all 4 cores and my system is running fine. I have also disabled EIST but kept c0 and c1E states enabled because i think my system is having problems managing voltage and speed to the cpu and chipset. So its better to not let cpu speed get up or down..make it stay put @ stock 2.66 ghz speeds. I am thinking should i select cpu idle state to 'high performance' ? so that it runs at all times in a fixed speed and stepping ?

I dare not run anymore benchmarkers like prime 95 and stuff.

Let's get some terminology right
Benchmarking software are not stress testing softwares. So its not necessary benchmarking software will stress your system- it will only test how fast is that hardware component. Stress testing software doesnt not test a power supply too 100% load as well- it will only pull the power based on the system. Stress testing softwares do not blow your system- unless you are using substandard/defect product or you are over volting a component.
So to answer your question, you will have to tell me your system configuration.

[anoopingenius]

On the contrary, I think it might fall short or cut it too close. Logic: The combined max wattage on 12v is 216W, which means a max of 18 A. Isn't it?

So I think I'll go with the 460W one instead. It has a Max 12v Wattage of 312= 26A.

I just need to find out one thing: If the maximum 18A on 12V1 will support the graphics card+ 2HDD+ other peripherals. Can you help me on this?

Thanks a lot for your guide. It started me on to all what I learnt in the past 2 days!

[The Sorcerer]

^^ Mathematically speaking- yes. On papers it is supposed to be 26 amps. But in real world is somewhat different. Like I said, split rails will have some sort of DC loss compared to single rail- but that fact is also depending more on the load as well. DC power cannot be calculated but something that can be seen via a load tester. Most probably it gives 22-24 amps in DC. We should also consider the fact that this is a passive pfc- which kinda sucks since you arent able to get VIP psu. In your current rig, it wont be an issue. Split voltage funda differs from company to company so its pretty confusing.
Thanks for the appreciation BTW! I write guides based on the behaviour of the majority of the people so I usually write for 1 forum. But since this guide is pretty understandable, I have put this on majority of the forum who either have no guide- or an outdated/wrong one.

[mrsam1999]

Sorcerer here is my complete PC configuration:

Intel core i7 920 @ 2.66 ghz, c0/c1 revision,
intel dx58so x58 motherboard,
kingston 3 gb ddr3 1333 mhz RAM,
xfx 9800 gtx+ 512 mb video card (oced version of 65nm 9800 gtx)
Seagate 320 gb hdd,
LG dvd writer,
Acer AL1706 17" lcd,
Old creative speakers,
Zebronics realwatts pro 600 watts psu,
Frontech keyboard and mouse.

Please guide me on the qpi management, EIST, cpu idle power state in relevance to the power draw thru PSU. Why did my pc restart just after i completed the everest benchmarks ? And since then this happened 4 more times while just watching movies, playing really old games etc. Did i set something really conflicting in the bios ? I didn't overclock anything !!

[The Sorcerer]

i7 consumes a lot of power- same goes for 9800gtx+. Although I find it strange you are using such a firepower on a slapstick silly 17 inch screen Can you give me a cpu-z validation link?

[mrsam1999]

Here is my cpuz validation link :-

http://valid.canardpc.com/show_oc.php?id=556909

And a screenshot of gpuz :-

http://img530.imageshack.us/img530/5474/gpuzf.jpg

[The Sorcerer]

It goes without saying- change the psu to atleast corsair tx650. Possibility exists that one the memory might not be working properly OR you got a bad processor batch. Unfortunatly in either of case we will have to stress test it. If its the ram, then either it could be something which the defect have surfaced, but with those psu, possibility also exists that it might have damaged the rams...
BUT
Did you update the BIOS by any chance? Find the batch code on the i7's packaging and google for it. See if you find any search about this batch. If its the processor, then you should find out if anyone with the same batch code have made any reports on any tech forums. Also go to xtremesystems.org and lurk around, see if you find any thread in regards to this issue. Maybe there's a setting one need to do.

[hash!!]

hmm.. needed something like this.. help me out someone..

my specs:
asus M2N-E
athlon x2 4400+
8800GTS 320mb
2x1GB DDR2
1x320gb SATA hdd
1x250gb SATA hdd
2xDVD Burners
1xInternal Card Reader
Creative SB Live! pci soundcard
4-5 fans thrown around

i've been running all this on a CM extremepower 550Watt PSU all this while, and it seems to have run fine.. so i wanna sell that off now, and get a new PSU cause Im planning to get a new processor, probably a phenom 9950 or a 9850, whichever is compatible with my M2N-E (im still trying to confirm that from people who have experience or know about it), and considering the phenom's 100watt+ usage, i think i should get a better PSU.

So, what kinda PSU do i get? cause i was planning to go for an 700watt extremepower, (if they make that).. theres a power calculator on Asus' website, that gave me an approximation of about 650 watts on my current config.. i know theres more to PSU's than their wattages, but i need some solid advice here..
Is there something cheaper, but better i should go for?
my system remains on for long hours, and on load for atleast half the time its on, cause i need to render stuff every now and then.

cheers,
Hari

[The Sorcerer]

^^ Well the whole guide has a detailed explanation on how a power supply should be judged and bought. I am pretty sure when you read that, you can make decisions accordingly.

[hash!!]

heh.. now now, i wouldnt post that entire write-up (spent atleast 15 minutes on that!) if i had it all sorted in my head, right?
im confused as to which psu to buy..
but its cool if you have issues, i wont bother posting.. i'l just go try knock on some other doors.. thanks anyway..

cheers,
Hari

p.s: you should move the admins to make this a locked sticky, if you dont want people sacrileging your sacred 'thread'.. i posted cause i thought this was a discussion, not a thesis..

[ntomer]

Hi,

I bought a new rig day before couple of days ago. The configuration of machine is -

Processor - Intel E8400
MoBo -
RAM - 2*1GB, Kingston 800MHz
HDD - Seagate 500 GB, 7200.12, 32 MB buffer
DVD Writer - LG, Sata, 20x
GPU - XFX 7900GS

I bought a generic (Branded - Circuit) 400W PSU with this. Then somebody suggested me that this PSU might not be able to support this configuration, so I searched a bit and found this wonderful link. After learning a bit about PSUs, I checked my rig's PSU and it is only 14A on +12V, means effectively 168 W.

This I guess is way too low for this rig, so I am planning to upgrade my PSU, please suggest me which one should I go for. I am have thought of the following alternatives -

Cooler Master 390W
Cooler Master 460W
Corsair 400W

Alsowhen I checked my PSU, I found that connections aren't done as recommended in this thread, so I've clicked a few pics of it. Please tell me is it alright?

The PSU -



Connection view 1 -



Connection view 2, notice how the GPU has been powered from a cord coming out of the DVD power -



Thanks

Nitin

[The Sorcerer]

I checked my rig's PSU and it is only 14A on +12V, means effectively 168 W.

Maybe on paper, but real time would be different depending on the operational temps. Keeping the same current configuration in mind, Grab a cx400 or antec EA 430.
I am sure its just another intel board. Sad part about intel is their OEM is foxconn and they call themselves "original". They dont even bother to put heatsink on their south bridge. For a stock, they are enough, but leaving southbridge, northbridge and mosfets is something to be prevented at all cost to maintain the shell life of the board.

[ntomer]

Maybe on paper, but real time would be different depending on the operational temps. Keeping the same current configuration in mind, Grab a cx400 or antec EA 430.
I am sure its just another intel board. Sad part about intel is their OEM is foxconn and they call themselves "original". They dont even bother to put heatsink on their south bridge. For a stock, they are enough, but leaving southbridge, northbridge and mosfets is something to be prevented at all cost to maintain the shell life of the board.

Sorry, I forgot to mention the MoBo, it is Intel DG31PR.

Please check whether the connections done with the current PSU are alright? And if I for a Corsair CX400W, will I be able to connect it myself, or do you recommend to get it done by a pro. I am not a very techie kinda guy; although I am a Software Engineer, I complete my Engineering 11 years ago and have been in management role for last 5-6 year, so far away from techiedom

Thanks

Nitin

[The Sorcerer]

^^ No your questions are genuine and logical. Here's the thing. The problem is not the connection- Its all fine. But the problem is rail stability. Only real way to find a stability is using a load tester or an oscilloscope- some type of equipments which is not feasible for an end user. Reads from the multimeter is usually not accurate. measuring voltage spike, rail stability need different type of hardware. Softwares dont usually indicate accurate readings, but to an end user they do a pretty decent job. The thing, you need to check load on the rails during load because that is when the reading from a software is more accurate compared to idle. BUT doing stress testing on this psu is a risk job. Some of these power supplies dont even have any form of PFC. So any voltage spike can damage because newer tech is way more sensitive then the old ones in terms of power.
Let's take an example in the spirit of discussion between 2 techies. There 2 versions of cm extreme 600w-PCAR and PCAP. PCAP has passive pfc. PCAR doesn't have any pfc at all. To make silly, when coolermaster got lot of complaints, they replaced the cheap aluminum heatsink with a pure copper one and most probably put a passive pfc- so they labeled all the extreme series as passive series- whether it is aluminum or not. These are bit heavier than the cx400 and are cooler than the aluminum ones. But cx400 has active pfc and the efficiency is tested on 40 degrees operational temps. extreme series are tested on older specs that is 25 degrees Celsius.
Going for cx400 helps a long way.

[ntomer]

Thanx Sorcerer,

I've bought the Corsair VX450W for 4 grands; will try to install it myself tonight. Let's see how it goes

Thanks again,

Nitin

[The Sorcerer]

^^ Fantastic. After you change the psu, google iso image called memtest and burn the bootable image on a disc. Boot the system via the disk and let it run the memory test for 3-4 hours. Also google and download orthos and run a blend test for 4-5 hours. Test is necessary to run to be absolutely sure that no components are damaged because of the old psu- just a standard precaution i would recommend to prevent any issues that may come up in the future. But dont run the stress test on the old psu.

[The Sorcerer]

heh.. now now, i wouldnt post that entire write-up (spent atleast 15 minutes on that!) if i had it all sorted in my head, right?
im confused as to which psu to buy..

It is said- arrogance diminishes wisdom.
I told you to read the guide because I have made the recommendations with the pros and cons. If you didnt want to read the entire guide, if you scroll down (and it is perfectly clear), there are power supply recommendations being made for certain range (in terms of power consumption) allready. It is going to be the same thing I am going to advice so it doesn't make sense to say thing again.
As for the sticky, that is for the mods to decide. I haven't put up any request and usually I help other forums. Since the guide is pretty understandable for people who are end users and technically sound, I have made the thread here.

[hash!!]

It is said- arrogance diminishes wisdom.

no sh!t yoda!! hahahah.. sorry about that..
i read your guide. kudos, its in great detail, and its quite helpful..
just that im quite slow, hence i was still confused, for the simple fact that theres power calculators that recommend a wattage that i never used. and i know how amps matter too, and all that.. just that i couldnt figure whether i should go for a corsair or a cm.. anyway, its all good.. i shall do whats bound to work sureshot - buy more wattage...
oh, and sorry for the 'arrogance'.. i was tryin to pass it off as sarcasm, but we all deduce things in our own sweet way, dont we..
cheers!
Hari