New PSU or cannibalize old one?

[Scase]

So I'm working on a new build and it looks like it will be considerably lower TDP than my current one. Main culprits on the current system are the FX-8350 OC'd to 4.4ghz IIRC and my Sapphire Tri-x 290x OC'd to 1040gpu and 1300vram.

 

Most calculators put my usage around 660w and recommending a PSU of around 750, I'm currently using a Corsair HX850 a very very good PSU and not even 2 years old yet. However the new build is likely to be a 6600k/6700k with a 1070. This drastically drops the usage to about 460w, seemingly keeping the PSU outside of the efficiency range. 

 

My question is as the 850 is about 1.5yrs old and I dropped about 250$ish on it is it just cheaper to keep rolling with that one in the new system or would getting a lower wattage PSU save me more in the long run? Or is it negligible?

 

Thanks.

[newbornsoul]

AS you may know, if my memory serves me right, that psu reaches it's peak efficiency, around 90%, at about 50% load. 50% of 850, is around 425, so, roughly, the wattage you'll consume with the new system. in load, you'll reach your peak efficiency, therefore, having the great psu you have, i'd say: keep it. the tendency is for hardware to be more efficient, and that's a lot of "power supply" you have there. you'll only be "wasting" a bit of energy while idling... so... and even then... let's do some very basic math, shall we?

 

Let's suppose you would buy something along the lines of a 550x(not that i would recommend that, because i don't, but...), it's an extra ~120$ for the psu alone.

 

and let's push the crap out of it by pushing the full 460W , that's about 84% of the power supply power, so, as you can see in the graph, it will fall around 0.89% effiency, and that means, it would be pulling ~517w out of the wall... in the current psu you have, by my calculations, it's about 90% of the psu's effiency, so... it would fall in SAVING not only the 120 cost of the new psu, as well as 6w per hour, as your psu would be pulling only ~511w... i know... there are other things to have in account as having a new psu, energy loss, things like that... but... the difference is so negligible you won't notice it... 6w an hour is about 0.006kw. even if you have the pc on full load 24/7, it will be 0.006*0.15$*24*365=7.884$ per year... and that's what you save by keeping your current psu... yeahy! lol let me say this again: these are very, very "simplified measures", in real life you have to take other things in account, but, your psu is perfect, that's kindof the sweet spot. do not ruin it... eheheheheh 

 

Hope i've aided in some way... Water bro (because i do not drink beer...)

 

The effieciency chart is available at the corsair's site

Your PSU:http://www.corsair.com/en/hx-series-hx850-power-supply-850-watt-80-plus-gold-certified-modular-psu

Chart only: http://www.corsair.com/en/~/media/83A09B87D2A24ECE82BC6BC7C65F0ADF.ashx?w=625

 

RM550x: http://www.corsair.com/en/rmx-series-rm550x-550-watt-80-plus-gold-certified-fully-modular-psu-kr

Chart only http://www.corsair.com/en/~/media/A40BF70DCB6D4485961F26E8E01E7130.ashx?w=625

 

P.S.: I would wait for the ZEN CPUS to get out... even if they suck, or aren't that good, intel will have to go down in their prices...

 

[Scase]

2 minutes ago, newbornsoul said:

AS you may know, if my memory serves me right, that psu reaches it's peak efficiency, around 90%, at about 50% load. 50% of 850, is around 425, so, roughly, the wattage you'll consume with the new system. in load, you'll reach your peak efficiency, therefore, having the great psu you have, i'd say: keep it. the tendency is for hardware to be more efficient, and that's a lot of "power supply" you have there. you'll only be "wasting" a bit of energy while idling... so... and even then... let's do some very basic math, shall we?

 

Let's suppose you would buy something along the lines of a 550x(not that i would recommend that, because i don't, but...), it's an extra ~120$ for the psu alone.

 

and let's push the crap out of it by pushing the full 460W , that's about 84% of the power supply power, so, as you can see in the graph, it will fall around 0.89% effiency, and that means, it would be pulling ~517w out of the wall... in the current psu you have, by my calculations, it's about 90% of the psu's effiency, so... it would fall in SAVING not only the 120 cost of the new psu, as well as 6w per hour, as your psu would be pulling only ~511w... i know... there are other things to have in account as having a new psu, energy loss, things like that... but... the difference is so negligible you won't notice it... 6w an hour is about 0.006kw. even if you have the pc on full load 24/7, it will be 0.006*0.15$*24*365=7.884$ per year... and that's what you save by keeping your current psu... yeahy! lol let me say this again: these are very, very "simplified measures", in real life you have to take other things in account, but, your psu is perfect, that's kindof the sweet spot. do not ruin it... eheheheheh 

 

Hope i've aided in some way... Water bro (because i do not drink beer...)

 

The effieciency chart is available at the corsair's site

Your PSU:http://www.corsair.com/en/hx-series-hx850-power-supply-850-watt-80-plus-gold-certified-modular-psu

Chart only: http://www.corsair.com/en/~/media/83A09B87D2A24ECE82BC6BC7C65F0ADF.ashx?w=625

 

RM550x: http://www.corsair.com/en/rmx-series-rm550x-550-watt-80-plus-gold-certified-fully-modular-psu-kr

Chart only http://www.corsair.com/en/~/media/A40BF70DCB6D4485961F26E8E01E7130.ashx?w=625

Awesome man! That was a huge help, thanks a ton!

[newbornsoul]

Just now, Scase said:

Awesome man! That was a huge help, thanks a ton!

By the way, not sure if you've noticed, if i we're you, i would wait for zen to get out, if you can keep the 8350 for some time more,  even if they suck, or aren't that good, intel will have to go down in their prices... 

[Scase]

Just now, newbornsoul said:

By the way, not sure if you've noticed, if i we're you, i would wait for zen to get out, if you can keep the 8350 for some time more,  even if they suck, or aren't that good, intel will have to go down in their prices... 

I wanna wait for Zen and the high end Polaris cards but, That's Q1 of 2017 at the earliest, not sure if I want to. My graphics card is not doing too hot. One of the fans LITERALLY spun off and fell into my tower, while the other 2 are rubbing against the shroud and clicking as they do. 

I will never buy a sapphire product again

[newbornsoul]

Just now, Scase said:

I wanna wait for Zen and the high end Polaris cards but, That's Q1 of 2017 at the earliest, not sure if I want to. My graphics card is not doing too hot. One of the fans LITERALLY spun off and fell into my tower, while the other 2 are rubbing against the shroud and clicking as they do. 

I will never buy a sapphire product again

it would be kind of a "ghetto" solution but you can add 2 120mm fans if you have them laying around, or 92mm if you need to buy them (i still would get the 120mm) and connect the fan to a hub if your case has one (for manual control) or to the mobo and tweak a bit with the speeds in the bios (for auto control), and strap them to the heatsink with a couple of zipties... believe it or not, it will be quiet (even quieter than now) and cooler, if you choose some good fans, for instance, linustechtips noctua fans... they are very good and quiet (as he is a silence freak, (sorry linus but you know you are...))... or you can go along with something like this (also ghetto) 

 

 

 

 

(That's not me by the way, i also have a beard, but my wife say's i'm better looking than he is... lol)

[newbornsoul]

Just now, Scase said:

I wanna wait for Zen and the high end Polaris cards but, That's Q1 of 2017 at the earliest, not sure if I want to. My graphics card is not doing too hot. One of the fans LITERALLY spun off and fell into my tower, while the other 2 are rubbing against the shroud and clicking as they do. 

I will never buy a sapphire product again

it would be kind of a "ghetto" solution but you can add 2 120mm fans if you have them laying around, or 92mm if you need to buy them (i still would get the 120mm) and connect the fan to a hub if your case has one (for manual control) or to the mobo and tweak a bit with the speeds in the bios (for auto control), and strap them to the heatsink with a couple of zipties... believe it or not, it will be quiet (even quieter than now) and cooler, if you choose some good fans, for instance, linustechtips noctua fans... they are very good and quiet (as he is a silence freak, (sorry linus but you know you are...))... or you can go along with something like this (also ghetto) 

 

 

 

 

(That's not me by the way, i also have a beard, but my wife say's i'm better looking than he is... lol)

[Scase]

3 minutes ago, newbornsoul said:

it would be kind of a "ghetto" solution but you can add 2 120mm fans if you have them laying around, or 92mm if you need to buy them (i still would get the 120mm) and connect the fan to a hub if your case has one (for manual control) or to the mobo and tweak a bit with the speeds in the bios (for auto control), and strap them to the heatsink with a couple of zipties... believe it or not, it will be quiet (even quieter than now) and cooler, if you choose some good fans, for instance, linustechtips noctua fans... they are very good and quiet (as he is a silence freak, (sorry linus but you know you are...))... or you can go along with something like this (also ghetto) 

 

 

 

 

(That's not me by the way, i also have a beard, but my wife say's i'm better looking than he is... lol)

Lol I might just try that, I have a couple extra 120mm noctuas kicking around from my old heatsink.

[STRMfrmXMN]

All that nonsense about "peak efficiency of a PSU" is worthless since all operate differently. What should be of importance is whether or not you should keep this PSU. Yes, there's no reason to get rid of it so why do that

[newbornsoul]

On 29/08/2016 at 11:42 PM, STRMfrmXMN said:

All that nonsense about "peak efficiency of a PSU" is worthless since all operate differently. What should be of importance is whether or not you should keep this PSU. Yes, there's no reason to get rid of it so why do that

that's the same as saying that there's no point comparing a i5-4690k and an i7-3770k... they work differently, they have different specs, however they have the same basic function... process your data... the same as comparing 2 psus... they power your pc... and there's a reason i chose comparing two corsair psus, both gold rated for 80plus, and both recent... they kind of work similarly... there are other things to account for when you compare psus, and i was very clear on that, but the difference those things will do will be impossible to see on the electrical bill... if you actually have some usefull input, please, i would love to learn something new... but saying "yeah, just don't change your psu because of no reason at all" is a bit vague...