FSP Everest PSU

[attacus]

Which PSU is best for me?
I have a hd 5850 on the way and Q6600 G0 with me, and expect to overclock both. I may crossfire in the future and I may get an i series chip along the line. Which of these PSUs are best?
http://www.ebay.co.uk/itm/FSP-Everest-800W-85-Plus-Modular-Power-Supply-Psu-1-x-20-4-Pin-Main-Connector-/140601271141?pt=UK_Computing_PowerSupplies_EH&hash=item20bc7d2365
http://www.ebay.co.uk/itm/FSP-Everest-700W-85-Plus-Modular-Power-Supply-Psu-1-x-20-4-Pin-Main-Connector-/120785397823?pt=UK_Computing_PowerSupplies_EH&hash=item1c1f5ee83f
Are 100W worth £10? Is 85+ bronze better than 80+? Also, is a PSU more efficient or environmentally friendly at 700W than 800W?

 

[Silvune]

If I was going to spend £65 on a PSU I would not buy either of those as I don't know that much about them; can't find any high quality reviews that I can easily understand/trust.
One thing I have managed to find out quickly is that the 700W FSP unit you are thinking of does not have enough PCIe connectors to crossfire 5850s, as such a build needs four of them. While the 700W unit only has two (which is very poor for a ~650W unit, let alone a ~700W one). The 800W does indeed have four.

And I'm aware of a few other PSUs at that price point that I do know something about and do trust. Which include:
Thermaltake Toughpower XT 675W 80Plus Bronze Modular £63
http://www.ebuyer.com/234912-thermaltake-675w-toughpower-xt-modular-psu-tpx-675m

XFX Pro 650W Core Edition 80Plus Bronze £63
http://www.scan.co.uk/products/650w-psu-xfx-p1-650s-nlb9-85-eff-80-plus-bronze-sli-crossfire-eps-12v-quiet-fan-atx

~650W is plenty to crossfire 5850s, as attested to by the numbers in this link:
http://www.tomshardware.com/reviews/radeon-hd-5850,2433-13.html
Shows a system using an i7-975 drawing 469W at the wall under Furmark. If you take 10-20% off that number you will have an idea of how much power their system actually needed.
A 425W load would only stress a 650W PSU to 65%. But that is almost unrealistically high, it would only ever be achieved infrequently, unless you run very demanding programs on a regular basis, but if you did draw that much it would be well within the capabilities of a high quality 650W PSU, like the two I have mentioned.

 

[attacus]

If I was going to spend £65 on a PSU I would not buy either of those as I don't know that much about them; can't find any high quality reviews that I can easily understand/trust.
One thing I have managed to find out quickly is that the 700W FSP unit you are thinking of does not have enough PCIe connectors to crossfire 5850s, as such a build needs four of them. While the 700W unit only has two (which is very poor for a ~650W unit, let alone a ~700W one). The 800W does indeed have four.

And I'm aware of a few other PSUs at that price point that I do know something about and do trust. Which include:
Thermaltake Toughpower XT 675W 80Plus Bronze Modular £63
http://www.ebuyer.com/234912-thermaltake-675w-toughpower-xt-modular-psu-tpx-675m

XFX Pro 650W Core Edition 80Plus Bronze £63
http://www.scan.co.uk/products/650w-psu-xfx-p1-650s-nlb9-85-eff-80-plus-bronze-sli-crossfire-eps-12v-quiet-fan-atx

~650W is plenty to crossfire 5850s, as attested to by the numbers in this link:
http://www.tomshardware.com/reviews/radeon-hd-5850,2433-13.html
Shows a system using an i7-975 drawing 469W at the wall under Furmark. If you take 10-20% off that number you will have an idea of how much power their system actually needed.
A 425W load would only stress a 650W PSU to 65%. But that is almost unrealistically high, it would only ever be achieved infrequently, unless you run very demanding programs on a regular basis, but if you did draw that much it would be well within the capabilities of a high quality 650W PSU, like the two I have mentioned.

Ok but if I had two PSUs, one 600w and one 1200w, but the same components on each, would the prices show up the same on my energy bill?
Also, is 85 plus no better than 80 plus then?

 

[Silvune]

85 plus is better than 80 plus. As it refers to the 80plus certification system. Where 80Plus Bronze is more efficient than 80Plus standard. 80Plus requires that units are 80%-82%-80% efficient at 20%-50%-100% loads. While Bronze requires 82%-85%-82% efficiency at those same load levels.
As for a 600W unit versus a 1200W unit, it depends on the efficiency of the unit. For instance if you have an 80Plus standard 1200W and were only using 50% it would be 82% efficient, but if you had an 80Plus Bronze 600W unit and it had to power the same system it would also be 82% efficient.
With the 1200W unit you are much more likely however to be spending a lot of time in its most inefficient zone; below 20%, whereas with the 600W unit you would be spending more time in the zone which the manufacturer will have focused on to get the unit to achieve the 80Plus certification; which should be more efficient.
But the efficiency curves of PSUs varies a lot between different units, some peak well below 50%, some peak after. Some units reach 80% more quickly than other units.

Hopefully I have explained it well enough for you to understand.

 

[attacus]

85 plus is better than 80 plus. As it refers to the 80plus certification system. Where 80Plus Bronze is more efficient than 80Plus standard. 80Plus requires that units are 80%-82%-80% at 20%-50%-100% loads. While Bronze requires 82%-85%-82% at those same load levels.
As for a 600W unit versus a 1200W unit, it depends on the efficiency of the unit. For instance if you have an 80Plus standard 1200W and were only using 50% it would be 82% efficient, but if you had an 80Plus Bronze 600W unit and it had to power the same system it would also be 82% efficient.
With the 1200W unit you are much more likely however to be spending a lot of time in its most inefficient zone; below 20%, whereas with the 600W unit you would be spending more time in the zone which the manufacturer will have focused on to get the unit to achieve the 80Plus certification; which should be more efficient.
But the efficiency curves of PSUs varies a lot between different units, some peak well below 50%, some peak after. Some units reach 80% more quickly than other units.

Hopefully I have explained it well enough for you to understand.

But isn't a PC more stable if you have more wattage than you need? Until I crossfire, would I even fall into the peak efficiency category? How do I battle efficiency with power leway?
Secondly, I found a review of an Everest 500, calling it an adequate PSU. I don't think Everest is a bad brand:
http://www.tomshardware.com/reviews/500w-psu-power-supply,2658-6.html
Also, I found a PSU that is 600w and 80 plus gold. However, I've never heard of the brand (ironically):
http://www.ebuyer.com/278518-be-quiet-ep-600w-80plus-gold-psu-bn188

 

[Silvune]

Aslong as the PSU is built well, high quality etc then there is no issue of stability if the PSU is under 100% load, it is just an issue of heat and fan noise. Possibly longevity is reduced, but as far as I'm concerned this is not much of an issue as most high quality units have MTBF figures of ~11 years, which is calculated with them running at 100% load at 25C.

In the link I posted earlier it showed a single 5850 using 305W under full load and 145W under idle. So it is likely that if a ~650W PSU was used then it would fit into the targetted 80Plus efficiency envelope.

Power leeway, should be a primary concern either when going for a very power hungry system, with two very power hungry GPUs or when you want to give yourself a very large amount of upgrade options. I think efficiency is taken care of by going for a minimum of 80Plus Bronze and/or getting a unit that is appropriate to the build.

The FSP Everest 85+ series probably isn't that bad, but the reason I am hesitant with older FSP units is that some of their Everest PSUs are not very good at all.

I think/have read an inference that the Be Quiet EP 600W is based on the FSP Aurum Gold 600W, but with a quieter fan; according to the respective websites the FSP's fan is rated at 24-38dBA, while the Be Quiet is rated at 15-39dBA. So if that is true then it is a solid choice. Generally Be Quiet are a well respected brand, unfortunately they sometimes have the habit of selling some units at a more expensive price than some people think they are worth based on performance.