Power Supply: Buy cheap or Future-Proof?

[WaiWai]

1)
Should I buy a more powerful power supply (for future-proof) or should I simply buy what I need?

Things to consider:
- If I buy just what I need, the price will be cheaper. Higher-watt power supply tends to be more expensive (small rise in watt, big rise in price).
eg:
380W: US$61.3
430W: $70.7
500W: $87.4
550W: $101.5
650W: $121.2
- Every now and then new technology comes, new types of cables may be required. Then my power supply will die out. 🙁
-- The workaround would be to use adapters. But are there any disadvantages/problems?

2) Is it okay to use old power supply (missing 8-pin CPU cables & SATA cables & PCI Express Cables) as long as it has enough total watt to supply?
Are there any big problems when using adatpers as workarounds?

3) If I want to use SLI/CrossFire, must I need to buy power supply which is SL/CrossFire certified?

 

[BassBomb]

There is no such thing as future proof..

Buying a quality brand is the most important thing + looking at amperage. Finally look at the watts.

If you are on a tight budget the Earthwatts line is the best. (380w - 500w)
If you are on a midrange budget then Corsair line is the best. (450w - 750w)
If you are on no budget then alot of high end brands like PC Power and Cooling would fit the bill (assuming you are needing all that power)

Personally I would fall in the middle with Corsair.

 

[Zap]

There is no such thing as future proof...

OMG, is there an echo in here? 😕

Originally posted by: WaiWai
1) Should I buy a more powerful power supply (for future-proof) or should I simply buy what I need?

2) Is it okay to use old power supply (missing 8-pin CPU cables & SATA cables & PCI Express Cables) as long as it has enough total watt to supply?
Are there any big problems when using adatpers as workarounds?

3) If I want to use SLI/CrossFire, must I need to buy power supply which is SL/CrossFire certified?

1) you HAVE to get at minimum what you need now. For "future" perhaps take some time to seriously think about your upgrade plans for the next year or two, and cater around that. For instance if you really, really want to go dual GTX 280 with your Christmas bonus, then buy that kilowatt PSU now (Nvidia hasn't certified anything less than 1kW for GTX 280 SLI). If you tend to have a 3 year upgrade cycle, then buy for now and plan to upgrade PSU in 3 years.

2) Yes, except you're using the wrong metric. Don't base it on the "total wattage" but base it on quality and amperage per voltage.

3) Certification means it should work. Non-certified doesn't mean it can't work, just that you'll have to do some research to make sure that it should work. If you want a "no brainer" then go certified, otherwise you take your chances, but have greater selection.

 

[Magusigne]

I think you guys are overreacting a bit on the "No such thing as future proof" remarks.

All be it you guys have 40,000 more posts than me🙂

My personal opinion in this matter is that I believe a good 750w PSU would be the best bang for the buck (future proof or otherwise)

Such as the Corsair 750tx?

I mean the way I planned my rig is to invest money in a good case and PSU as I was going to carry those through on my next few builds switching out the Mobo and all other components.

maybe thats just me, but I think its pretty fair to say that you should invest money in your PSU, that way it can carry you through some upgrades. (and also not fry your rig!)

 

[BassBomb]

What Zap said is spot on, if you are upgrading often then buying a nice PSU early is a good idea. If you are upgrading rarely much out of product cycles you will likely need new PSU's due to new connectors and new wattage requirements.

 

[Zap]

Originally posted by: Powernick50
I think you guys are overreacting a bit on the "No such thing as future proof" remarks.

I stand by my statement. See this thread on new PSU connector from the past few years. That's nothing to be said about decreasing importance in 3.3v and 5v, with increasing importance on +12v.

You can "future resistant" a purchase by buying a lot more than you need now, but nothing is "proof." Of course people can point out examples on both sides of that - someone using a 5 year old PSU to power a modern system and someone needing to replace a couple-year-old PSU because something new came out.

The other thing is that capacitors age, and PSUs are filled with capacitors. I don't think I'd want to be using my Corsair TX650 in five years, no matter how good it is right now.

 

[WaiWai]

I'm using this site as my PSU calculation: http://web.aanet.com.au/SnooP/psucalc.php

Current Use:
Mobo: Foxconn P35A-S, Intel P35 chipset, two PCI-Express x 16
CPU: E2180 O/C to 3.0Ghz (The PSU calc list doesn't have E2180, so I select E4700 for the calc)
RAM: DDR2 800 2GB*2 or 2GB+1GB or 1GB*3
Graphic card:
A) HD 2600 Pro (will O/C), Dual DVI outputs
B) HD 2400 Pro, Dual DVI outputs [not for Crossfire]
Monitor: 20-22", 1680x1050, * 4
HDD * 1
DVDRW * 1

Calculation Result:
(Note: the calculation has added plenty of headroom in the recommendation, according to the author)
Recommended PSU wattage for decent brand PSU: 277W
Recommended 12V combined amps / watts for decent brand PSU: 18.6 A / 223 W
Recommended 3.3V Amps: 5.4A
Recommended 5V Amps: 3.9A
Recommended 3.3V/5V Combined Watts: 31W

Possible Future Use (Minor Upgrade within 3 years):
Mobo: Foxconn P35A-S, Intel P35 chipset, two PCI-Express x 16
CPU: Any Quad-Core CPU (will O/C) (I select Extreme QX9650 for the calc)
RAM: DDR2 1333 2GB*4
Graphic card:
A) HD 4850 (will O/C), Dual DVI outputs
B) HD 2400 Pro, Dual DVI outputs [not for Crossfire]
Monitor: 20-22", 1680x1050, * 4
HDD * 2
DVDRW * 1
Blue-ray Burner * 1 (There is no blue-ray burner in the PSU list so I select 1 more DVDRW)

Calculation Result:
(Note: the calculation has added plenty of headroom in the recommendation, according to the author)
Recommended PSU wattage for decent brand PSU: 447W
Recommended 12V combined amps / watts for decent brand PSU: 32.1 A / 386 W
Recommended 3.3V Amps: 9.5A
Recommended 5V Amps: 3.9A
Recommended 3.3V/5V Combined Watts: 44W

Future Major Upgrade (after 3-4 years):
Who knows what the technology will be after 3 years?
I will most likely make a budget/mainstream build only (not high-end builds!)

Note:
* I don't expect I will upgrade my computer within 3 years.
* I will only buy quality brand / PSU.
** Excess-watt approach: Dearer but more room for future expansion. I expect to use it for 6-9 years, ie the PSU will follow me for the current and next 1-2 major upgrades. But I wonder if new technology will kill my PSU after 3-4 years anyway. Another concern is aging. How serious is it? If I go for this route, I will probably select 500W-700W (?).
** Enough-watt approach: It's enough to power my current system. And it saves me money. I would simply go for 300-450W PSU.

=========================================================

Question:
What PSU would you suggest in my cases?
I would like to buy Uninteruptable Backup Power for my desktop computer. What would you suggest?

 

[WaiWai]

You can "future resistant" a purchase by buying a lot more than you need now, but nothing is "proof." Of course people can point out examples on both sides of that - someone using a 5 year old PSU to power a modern system and someone needing to replace a couple-year-old PSU because something new came out.

Hmm... Another point we can consider is the use of adapter. This can extend the life of the power supply. 🙂
However I'm a bit worried about the use of adapters of high-current supply. Those seems to be high-current supply:
* 24-pin ATX main power cable
* 4-pin CPU cable
* 8-pin CPU cable
* 6-pin PCI Express Cable
* 8-pin PCI Express Cable

My concerns are bold. If my power supply don't have those those cables, what can I do? Can I still use adapters as workaround?

6/8-pin PCI Express Cable has three +12V wires. If I use 4 pin peripheral connector adapters, we use 2 peripheral to convert into PCI Express connector. But I only get two +12V wires in this way.

8-pin CPU cable. It has four +12V wires. If I use 4 pin peripheral connector adapters, we use 2 peripheral to convert. But again I only get two +12V wires in this way.

ATX 20+4 pin main power cable. I wonder if it's ok to use 20-pin power cable + 4 pin ATX +12 volt power cable (for CPU) to match the 24-pin requirement.

 

[BassBomb]

seriously i would reccomend NOT using a psu after 6 years unless it remains powering the same system you bought it with (or upgraded to)

so when you do your major upgrade after 3 years buy a new psu...

 

[Jessica69]

Originally posted by: WaiWai

Hmm... Another point we can consider is the use of adapter. This can extend the life of the power supply. 🙂
However I'm a bit worried about the use of adapters of high-current supply. Those seems to be high-current supply:
* 24-pin ATX main power cable
* 4-pin CPU cable
* 8-pin CPU cable
* 6-pin PCI Express Cable
* 8-pin PCI Express Cable

My concerns are bold. If my power supply don't have those those cables, what can I do? Can I still use adapters as workaround?

6/8-pin PCI Express Cable has three +12V wires. If I use 4 pin peripheral connector adapters, we use 2 peripheral to convert into PCI Express connector. But I only get two +12V wires in this way.

8-pin CPU cable. It has four +12V wires. If I use 4 pin peripheral connector adapters, we use 2 peripheral to convert. But again I only get two +12V wires in this way.

ATX 20+4 pin main power cable. I wonder if it's ok to use 20-pin power cable + 4 pin ATX +12 volt power cable (for CPU) to match the 24-pin requirement.

The answer to your last question is no.

The answer to all your other concerns is simple.....go buy a power supply of sufficient wattage needed with the proper cabling. I have never been a fan of trying to adapt one or more Molex-ended cables to PCI-e connectors, especially if you need more than one.

You take a very risk in overloading a rail without knowing you're doing it until it's too late because in most all power supplies, the peripheral cables, your SATA, Molex, etc., are on a single rail and unless you have one single, massive railed ps, it won't support pulling the necessary wattage for an uplevel video card and your hard drives and other peripherals. Then again, if you have a power supply with a single, massive +12V rail, chances are you already have a modern power supply with all the other necessary cables, anyway.

 

[WaiWai]

I did have an decent-brand old PSU which is 500W, 3 years old. But I'm not going to use it to power my next build.

I have friends who asked me such kinds of questions ago. I'm interested to know if it works technically assuming that the power supply has enough power but it doesn't have the right connectors.

The adapters can transfer most wires (although I see some missing I don't know if it matters much) and so most power, I believe.

If adapters can't help at all, there's one point less to support buying a much more powerful PSU for future-resistance.

 

[jonnyGURU]

Originally posted by: BassBomb
seriously i would reccomend NOT using a psu after 6 years unless it remains powering the same system you bought it with (or upgraded to)

so when you do your major upgrade after 3 years buy a new psu...

This is actually pretty good advice. Sure, some PSU's have 7 year and lifetime warranties, but the fans in the PSU's don't even typically last that long. They're usually the first thing to fail and when they do, the resulting PSU failure can leave you without a PC until you can get a replacement. Never mind the potential of swollen caps and everything else that can happen to a PSU when it gets old.

 

[WaiWai]

Originally posted by: jonnyGURU

Originally posted by: BassBomb
seriously i would reccomend NOT using a psu after 6 years unless it remains powering the same system you bought it with (or upgraded to)

so when you do your major upgrade after 3 years buy a new psu...

This is actually pretty good advice. Sure, some PSU's have 7 year and lifetime warranties, but the fans in the PSU's don't even typically last that long. They're usually the first thing to fail and when they do, the resulting PSU failure can leave you without a PC until you can get a replacement. Never mind the potential of swollen caps and everything else that can happen to a PSU when it gets old.

Yes fan is more likely to fail first. However we can replace the damaged fan (although some work and knowledge required).

So what left is the aging of capacitors? How serious is it? How much percentage of actual output will be reduced?

What's the average lifespan of a PSU?

 

[WaiWai]

I'm curious about adapters. Is it just a marketing stuff which is useless? I want to know more about it.
How does it work? How can it convert so the old cable can supply what the new cable requires?
Does it technically work if we assume is able to draw high power? What's the drawback? How serious?

Take a look at 6-pin PCIe cable. It officially supplies 75W only. But a peripheral cable can supply 60W from one +12V wire. Why do they create a new 6-pin PCIe cable when the old peripheral cable is able to do what it does? It doubts me.

 

[DSF]

Originally posted by: WaiWai
Yes fan is more likely to fail first. However we can replace the damaged fan (although some work and knowledge required).

So what left is the aging of capacitors? How serious is it? How much percentage of actual output will be reduced?

What's the average lifespan of a PSU?

Especially now that PSUs are using quiet 120mm fans, I'm not sure how likely people would be to notice a fan failure unless it started whining as it went out.

 

[WaiWai]

Especially now that PSUs are using quiet 120mm fans, I'm not sure how likely people would be to notice a fan failure unless it started whining as it went out.

Well actually all fans are subject to failure. CPU, graphic card, case fan, PSU fan.
It seems we should keep monitoring them to prevent hardware damage.

But I believe even if we don't, the computer just shut down because it's getting too hot.

Software which will monitor fan speeds may help. But I never use one.