Need help downgrading PSU

[EndersShadow]

After much thinking (and looking at UPS costs for my rig's) I have decided I need to downsize the graphics card in my main rig. I currently have a 4870x2 and had planned on running 2 4870x2 at some point for graphic purposes. Realizing I wont see any significant video rendering gains from this (and since I dont play computer video games) am now looking at something along the lines of a 5450 like this + a ATI FirePro 4800 like this.

I need the 5450 to get bitstream audio over HDMI since my computer is hooked up to a Denon 1610 via HDMI and then a HP2509m monitor. I do have an internal blu-ray player and am planning on building a 5.1 system for my computer (currently running 2 channel and building up)

My question is what kinda power would I need to run both of those? I am hoping to be able to drop my PSU from a 1000 watt to perhaps something in the 500-700 watt range (like this one). Is that realistic or can I go even lower? I looked and just about all of the FirePro cards list only a 350 watt PSU needed and the 5450 does not require any PSU connectors. The rest of my spec's are listed in my sig.

 

[von-scott-aka-shredz]

I am going from 3 xfx gts 250 core editions, to 3 xfx gtx 280's right now I have a brand new xfx black edition 850 watt but need more to power the 3 cards I have on order what psu do you have maybe we can work something out. i really dont believe it will hurt to have to much wattage and unless you are trying to save the planets energy.it dont relly matter.you never know you might want to add something down the road. you could try going to neweggs psu calculator add what hard ware your sys. has and it will make a wattage recomendation.

 

[EndersShadow]

I am going from 3 xfx gts 250 core editions, to 3 xfx gtx 280's right now I have a brand new xfx black edition 850 watt but need more to power the 3 cards I have on order what psu do you have maybe we can work something out. i really dont believe it will hurt to have to much wattage and unless you are trying to save the planets energy.it dont relly matter.you never know you might want to add something down the road. you could try going to neweggs psu calculator add what hard ware your sys. has and it will make a wattage recomendation.

The current PSU I have is a Kingwin Mach 1 1000w Modular PSU (link to spec's here). The reason I want to go as low as I can on the PSU is that in looking at the spec's for both graphics card (and even the 1k FirePro cards) they only need 250-400 watt powersupply. The 5450 (or 5570 havent decided which one to get yet) dont require a PCI-E connection from the PSU and the FirePro cards seem to only need a single 6pin (regardless of the model).

I am hoping to get a battery backup for both this system and my server. The current cost to get a battery backup for both systems is around 600+ due to the high requirements of my PSU. If I swap out graphic cards I not only get a boost in performance for video rendering, but also can save money on the UPS for the systems since I can get a cheaper one.

I might be interested in doing a swap if you are, I will let you know.

 

[blivit4]

That ATI FirePro appears to be based on the same Redwood GPU as the 5670, so it probably draws under 10w @ idle and <70w @ load. If you aren't OC'ing, then your system would be fine with a 400w PS.

 

[Redbeard]

You know that a 1000W PSU isn't always producing 1000W, right?

Assuming your new rig uses 200W at load, you'll be drawing 200W from the PSU, and because it's 80 Plus Bronze efficient, it'll be drawing a maximum of about 240-245W from the wall.

If you go down to, say, a 400W PSU that's also 80 Plus Bronze efficient, it will draw slightly less, say about 235W from the wall. So if that 5-10W is worth the downgrade to you, then go for it.

Personally I'd just leave it be, but if you're willing to make the downgrade for 5-10W (max) of power savings (unless you went with an 80 Plus Silver or 80 Plus Gold unit in that range) then so be it.

Even with an 80 Plus Gold unit, 400W, you'd still only be saving about 20W. Which is significant, but it won't make a real dent in your energy bill.

 

[EndersShadow]

You know that a 1000W PSU isn't always producing 1000W, right?

Assuming your new rig uses 200W at load, you'll be drawing 200W from the PSU, and because it's 80 Plus Bronze efficient, it'll be drawing a maximum of about 240-245W from the wall.

If you go down to, say, a 400W PSU that's also 80 Plus Bronze efficient, it will draw slightly less, say about 235W from the wall. So if that 5-10W is worth the downgrade to you, then go for it.

Personally I'd just leave it be, but if you're willing to make the downgrade for 5-10W (max) of power savings (unless you went with an 80 Plus Silver or 80 Plus Gold unit in that range) then so be it.

Even with an 80 Plus Gold unit, 400W, you'd still only be saving about 20W. Which is significant, but it won't make a real dent in your energy bill.

I do realize its not drawing a full load, however I am looking to buy a APC Battery backup. When talking to folks about which one to purchase they keep pointing me to the more expensive ones due to the fact that my PSU can draw at max 1275 w at full load. See below quote from this thread:

It doesn't seem like the AV line has anything powerful enough for your desktop. I'd look at the SmartUPS line which seems less expensive with more features.

I notice you haven't listed the power requirements of your monitor(s).

I looked up the Kingwin Mach 1 and the EarthWatts 430. Both are PFC power supplies, so they may draw large currents when the UPS transfers to battery. That's why we want to get a UPS that can handle their full load.

The Kingwin Mach 1's rated output power is 1000W, and is guaranteed 80% efficient or better. That means it could draw 1000W/0.8 = 1250W from the wall during fully loaded normal operation. But if you look at the AC input spec, they say they can draw even more power... 15A at 115Vac which is 1725W.

The EarthWatts 430's rated output power is 430W, and is also 80%+ efficient or better. That means it could draw 430W/0.8 = 537W from the wall during fully loaded normal operation. But if you look at the AC input spec, they say they can draw even more power... 7A at 100Vac which is 700W.

Here's how I would size for both computers:

We should probably size for 1250+537 = 1787W and ideally the UPS can handle momentary excess current. If you get the SmartUPS 2200 which can handle 1980W for your two computers. Then test the UPS by pulling the plug on it. If the computers stay on (most likely), great. If not, you can use it to back up your desktop and use another UPS for the server.

I dont want to overload the battery backup so I need to make sure it can handle a full load from the PSU's of one or both computers. As such if I can reduce the max load the PSU can pull from the battery backup (regardless of if the computer is using under that max load) I can purchase a cheaper battery backup as the one they listed is around 480 new and 335 used. I might end up with two different battery backups for each computer in the office so I can get cheaper units, but downgrading my PSU to one with a lower max load will help even more.

 

[Redbeard]

I do realize its not drawing a full load, however I am looking to buy a APC Battery backup. When talking to folks about which one to purchase they keep pointing me to the more expensive ones due to the fact that my PSU can draw at max 1275 w at full load. See below quote from this thread:


I dont want to overload the battery backup so I need to make sure it can handle a full load from the PSU. As such if I can reduce the max load from the PSU (regardless of what the computer is actually pulling from it) I can purchase a cheaper battery backup as the one they listed is around 480 new and 335 used.

Ah okay, sorry for my misunderstanding.

 

[EndersShadow]

Ah okay, sorry for my misunderstanding.

Not a problem, I skim threads and misread all the time . Any suggestions for me regarding what PSU's I should be looking at? I would prefer to keep it from one of the following companies (Silverstone, Corsair, PC Power and Cooling, Seasonic, Antec). Modulaw would be prefered but isnt required.

 

[Redbeard]

Not a problem, I skim threads and misread all the time . Any suggestions for me regarding what PSU's I should be looking at? I would prefer to keep it from one of the following companies (Silverstone, Corsair, PC Power and Cooling, Seasonic, Antec). Modulaw would be prefered but isnt required.

Obviously I recommend Corsair, but for your use the CX400 or VX450 would be more than enough.

Our lowest wattage modular product is the HX650 which is Bronze certified as well.

 

[sean1197]

the hx650 is a pretty good psu. I have one in my lil brothers pc and its been running fine now for 7 months no problems at all

 

[EndersShadow]

In looking at those PSU's thinking about going with the Corsair VX450. Any of the FirePro cards I would realistically buy only need 350w or more. I do have a couple additional questions:

1) If I take out the 4870x2 I have in my setup currently and install the 4550 would I be able to take out the PSU I am using and use my servers Antec Earthwatts 430 until I sell the 4870x2 and the PSU?

2) Anyone have any suggestion on what to sell the Kingwin for once I purchase the new PSU? Was thinking somewhere in the 100-150 range perhaps? Thoughts?

 

[EndersShadow]

someone? anyone?

Need help picking between the Corsair CMPSU-450VX or the Corsair CMPSU-400CX as well as answering the questions above....

 

[BillR]

someone? anyone?

Need help picking between the Corsair CMPSU-450VX or the Corsair CMPSU-400CX as well as answering the questions above....

If you go back to the rest of the post and look you will see that your current PSU and the smaller ones you are considering will all draw (within a few watts) from the wall, it’s all based on load.

Unless you feel you must spend money on a smaller PSU your UPS won’t know the difference. It’s based on real load, not the size of the PSU in this case.

 

[Zero82z]

someone? anyone?

Need help picking between the Corsair CMPSU-450VX or the Corsair CMPSU-400CX as well as answering the questions above....

Go with the VX450. It's better-built.

 

[EndersShadow]

From reading the limited reviews (only found one really) it seems that the 450 and the 400 watt PSU use almost all the same components except for

"The secondary from Corsair CX400W is absolutely identical to the secondary from Corsair VX450W, Antec EarthWatts 500 W and Arctic Cooling Fusion 550RF. So the main difference between Corsair CX400W and these other power supplies are the transistors used on the primary"

also there was this quote:

Internally Corsair CX400W is similar to Corsair VX450W, Antec EarthWatts 500 W and Arctic Cooling Fusion 550RF, but using less power transistors on the primary.

They also managed to pull 480 watts from the PSU before it shut down. I think after all that I will be going w/ the 400 watt version. Looking at the 5450 + V5800 (highest FirePro card I would ever buy) the only real requirements are that the V5800 needs a PSU w/ 75 watts for graphics card (which this PSU has). I think that almost seals the deal unless someone else has some good reasons not to save some cash by going with the 400 watt over the 450 watt?

 

[Zero82z]

Well, the VX450 has a better capacitor selection. But if you really want to save money then the CX400 should be fine.

 

[EndersShadow]

Well, the VX450 has a better capacitor selection. But if you really want to save money then the CX400 should be fine.

Getting married August 21st. Have a honeymoon to pay for (hence the extra 20 bucks being an issue). Attempting to sell a 4870x2, 4550 & Kingwin Mach 1 1000 watt PSU to get the cash for these parts, but so far no luck.

Only bite on craigslist I got wanted to trade for a full system, which isnt what I need.

 

[EndersShadow]

Went aheah and decided to take the long term approach and just bit the bullet and bought the 450 and the 5450 today. Once they come in and I get my rig setup again I can sell everything at once. Still waiting on purchasing the V4800 since its 200 dollars.