Need Help Explaining to a Friend...

[Cmustang87]

So I need a way to explain this to a friend. He currently has this power supply http://www.antec.com/specs/TPII550_spe.html. Judging by the spec sheets it has 2 12V rails with 19A on the rails.

As from what I know 19A is pretty low for a PSU, but he's saying he will not need to upgrade his power supply when he gets his new PC (i7 920, ATI 5770, 7200.12 500GB 'cuda). I recommended he looks at the Corsair 550vxpower supply, it powers it with a single beasly 41A 12V rail. From what I know 1 single rail with 41A should be way better then 2x 19A rails.

That is just that, it's what I know...but I'm not sure why this is. How can this be better explained to him so I can understand and he can as well?

 

[Dangman]

From what I know 1 single rail with 41A should be way better then 2x 19A rails.

Kind of. 2 x 19A rails pretty much means the max amperage on the +12V rail will only be 38A on the +12V rail. In reality, that PSU only has 36A total on the +12V rail. So in that case, a 41A single rail is better due to more amperage. WIth that said, if properly implemented, you really can't tell a difference between one and multiple rails if they have the same combined amperage.

That is just that, it's what I know...but I'm not sure why this is.

I highly recommend reading these PSU FAQs for more info:
http://www.jonnyguru.com/forums/showthread.php?t=1036
http://forums.anandtech.com/messageview.aspx?catid=84&threadid=2260432

For future reference, even a PSU with only 36A on the +12V rail split among two implemented properly 19A rails will be enough for your friend's setup. HOWEVER, he should still replace that PSU for an entirely different reason:

The Truepower I and II series as well as the Smartpower series were well known for their above average death rates due to a poor choice in caps and cooling design. In more specific terms, Antec/CWT specified/used caps (Fuhjyyu caps) that did not respond well to heat. Unfortunately, Antec made the decision to have the PSU fan only ramp at really high temps in an effort to keep the PSU quiet. However, just medium to high temps were enough to screw up the caps so really high temps were murderous. Over time, this degraded the quality and performance of those PSU series.

So I recommend replacing the PSU, especially if you hear a squeal, whine, or any odd noise coming from the PSU. Those are usually the first signs of those particular PSU lines dying. So if you do hear a squeal, whine, or any odd noise, that's enough grounds to replace the PSU.

 

[Menelmarar]

So I need a way to explain this to a friend. He currently has this power supply http://www.antec.com/specs/TPII550_spe.html. Judging by the spec sheets it has 2 12V rails with 19A on the rails.

As from what I know 19A is pretty low for a PSU, but he's saying he will not need to upgrade his power supply when he gets his new PC (i7 920, ATI 5770, 7200.12 500GB 'cuda). I recommended he looks at the Corsair 550vxpower supply, it powers it with a single beasly 41A 12V rail. From what I know 1 single rail with 41A should be way better then 2x 19A rails.

That is just that, it's what I know...but I'm not sure why this is. How can this be better explained to him so I can understand and he can as well?

I wouldn't recommend he spend money upgrading it. His current power supply should suffice. The corsair is certainly better, but since he already has the Antec, no reason to upgrade.

I doubt the 550 Antec will have a problem running that system. The lack of power will show itself in the form of having issues booting such as failing to boot, or blue screening, or random crashing. Even if you see those issues, I would clear other components to the best of your ability first such as 15 Memtest86 passes, one module at a time, substituting other components for alternates, etc. I generally find memory is the most likely culprit of system instability.

 

[RamonGTP]

He'll be fine. I prefer a large single rail over multiple smaller ones, but that doesn't mean the dual rail won't work. As stated above, there are certainly better PSU's, but there's no reason to spend additional funds if he already has the Antec. Heck, my cousin is running an i7 920 with 2 hard drives and a 4890 (which uses more power than a 5770) on a 500watt Antec Earthwatts that has a similar 12v rail loading with no issues.

 

[Dangman]

Just to be clear: I'm not saying that there's gonna be a lack of power. Far from it. I'm saying that the power provided may not be of good quality or clean. Considering the issues that entire line had, I can't recommend using that TP II PSU.

But yes I agree that even the Antec EA500 500W PSU will be enough for the planned setup. But we know that the Earthwatts 500W can handle the load. Not 100% sure that the Antec Truepower II 550W can considering the age and aforementioned design.

Besides think of it this way: a replacement PSU will only cost about $60 (The Antec Earthwatts 500W PSU noted by RamonGTP). Considering that the planned setup is of the following:
$290 - i7 930
~$210 - X58 mobo
~$105 to ~$160 - 4GB to 6GB of RAM
$165 - XFX HD 5770
$55 - Seagate 500GB HDD
------
Total: $825 to $880 give or take.

$60 is a small investment for a PSU guaranteed to be capable of its rated wattage without harming the PC.

 

[Cmustang87]

Thanks for the info. I'm going to redirect him to this thread so he can make a good judgment on his behalf. I still vote for a new PSU, but I'm very partial to what I power MY rigs with. His prorities might be different then mine and I don't to impede to much on his thoughts.

As for those links Danny_Bui, thanks I'll check those out, hopefully it will shine some light on the topic.