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Beginner builder gpu / psu question

Hi Everybody,

Last year, my 11 yo and I built a desktop pc. I am looking at upgrading his Gpu and psu, but online reviews have me worried. The Newegg calculator tells me I need 496w, but reviews say that some psu putting out as much as 570w will not be powerful enough to run the gpu.

Current setup:

Asus msa99 Fx pro r2.0 MB with 24 pin power
Amd fx 6 core processor w/fan
2 x 8g ddr3
7200 spd hd
GeForce gt 630
360w atx 12v v2.3

I was able to get my hands on a Zotac gtx 960 and would like to install it in this machine..... is this possible? It came with 2 - 6pin pci express cables. How do I determine the proper psu?

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Clarification Request
I don't see the full PSU make and model.

In reply to: Beginner builder gpu / psu question

You could share the number of +12V Rails and each rail's Ampere rating. But 360W is low. It might eek by if the PSU is new (they lose capacity with age) and was a single rail. But you never want to try this on any split rail PSU (more than one +12V rail.)

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In reply to: I don't see the full PSU make and model.

I agree. I would like to upgrade the psu wattage to north of 500w, but the customer reviews on websites like Newegg, suggest that 500w is not enough. I am trying to understand how to determine the appropriate wattage needed after installing the new gpu.

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Which is true. But why?

In reply to: Yes

I can hand you an 1000 Watt PSU that isn't enough. Why? Because I handed you a quad or more rail model which falls short of the amperes a rail needed to deliver.

It's not just Watts. This is something a new builder picks up later as they learn more.

This is why you will read 500 Watts isn't enough. Not only Watts but Amperes on the rails. To avoid this and make it easy you only need one thing. Get a single rail PSU.

I see from that folk have learned this as I didn't find a split rail model in the top 10.

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Makes sense

In reply to: Which is true. But why?

Ok. That makes sense to me. The current psu I am using is only rated for 20a on the 12v rail... a psu with 42a on the 12v rail should be more than I need to efficiently run a gtx 960 gpu, would you agree?

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You're pushing me here.

In reply to: Makes sense

There are more to specs than rails and amperes. There's also rush currents and more.

But 98% of the time you only need to get about 50% or more Watts then a single rail and you are done.

20 Amperes on the +12V is anemic today for gamer systems. When I figure out "is the PSU OK" I find the Watts for the card, usually the TDP and then pile that entirely onto the +12V Rail.

So 20 x 12 = 240 Watts. The TDP on the first hit for a 960 on google is 120 Watts so in theory it's OK for the GPU alone.

But you have the CPU at possibly 150W so without adding HDDs and more, we have blown our 240 Watt budget.

Power supplies are best not run at full load. I like to get back to about 50% load to assure long life.

The machine might boot OK but if it's like the usual, you'll get a collection of blue screen codes which the owner starts researching to find if there is an OS or driver failure.

-> Here's the deal. If you see a collection of blue screen codes, it's likely to be hardware. Causes can be power, heat, memory or other.

All Answers

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Round numbers

In reply to: Beginner builder gpu / psu question

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