[CL] Corsair Launches the AX860i, AX760i, AX860 & AX760 80 Plus Platinum PSUs - Page 8

(Big Smile)

Well we can blame George then ... I get where you're coming from there. I would say its just how one wants to interpret the documentation. If you look at the graph they show, it starts to ramp up at 30% and peaks at 40%, then climbs at a slower pace from there on. The AX860is shows it to start at 20% and peak at 30%, so they've brought that down just a little bit.

To answer your question about which would put less heat into the room. I've obviously had more time with the AX1200i compared to the AX860i, but will say at this time I would say the AX1200i is likely going to put the least amount of heat out at a low idle load like your talking.

My AX1200i's fan came on at roughly 30% = 360W, while the AX860i came on at roughly 20% = 172W. To me the AX1200i has the larger size and will likely benefit from it having its components spread out more. If you say you're averaging 200W @ idle most of the time. That would put the AX860i at just over a 23% load, while it would only put the AX1200i at a little over 16.5% of a load. So if your thinking strictly heat related, I would say its going to be easier (less heat) for the AX1200i to produce the 16.5% load, than it is for the AX860i to produce the 23% load. But then you have to factor in the price difference and the fact that the AX1200i sounds like it would be major OVERKILL .

So effectively the AX760 is a passive 530W thag can do 760 with a fan, at Platinum?

DO WANT.

Thanks Tazz, the extra cost is not a problem, nor is the re-cabling in order to install the AX1200i monster, I just want to choose the unit that will give less of a “space heater effect” at my low loads, I mostly just work in Microsoft Office for 9 to 11 hours a day. I know my whole rig is overkill for that, but I love a responsive pc and I love tech, fast and quiet and with the least amount of heat. I live in Florida and the summers even with A/C, well you get the idea.

I will buy either unit, even if I only ever use a single video card.

AX860i OR AX1200i.

Whichever unit you feel produces less heat into the room over many work hours at low loads 18 to 20%, whatever you guys say is best I will purchase.

Thanks again man, I am subscribed to JonnyGuru.com always. Best PSU reviews, has been for many years.

You've actually got this kind of backwards - the heat dumped by the PSU will be whatever it doesn't convert to DC, so you want it operating at high efficiency (where it's converting nearly all the AC to DC rather than turning it into heat).

All PSUs struggle to be efficient at very low loads, and if you look at efficiency graphs the difference in efficiency between say 30% and 90% load will be quite small, wheras below 20% the efficiency absolutely plummets.

If you don't want too much waste heat dump, you want to be operating in the efficient regime above 20% load, and preferably above 30%.

Just to put this in perspective however, let's say you compared the heat dump of 2 PSUs - one 80% efficient and one 90% efficient, each at a 200 watt "desktop usage load". The 90% efficient one would generate 22 watts of waste heat, and the one that was only 80% efficient would generate 50 watts of waste heat, a difference of 28 watts which is less than the heat output of a candle.
Edited by BorisTheSpider - 11/10/12 at 2:36pm

Yep getting a AX860i for sure

My comment is based off of actual usage and what I felt that day. I didn't confirm any numbers. From touch it felt like the 1200i was the cooler of the two units. I'm not disagreeing that the 860i should be the lesser of the two. The fact that the 860i is more compact than the 1200i has to also be factored in, as it will affect how well the unit passively cools itself until the fan kicks on.


He's talking about the 170W ~ 200W range which is where my rig idles and runs most of the time. Having tested both PSU's in that rig for the software side of it is where I was coming from. As I said, I agree that you want the unit to be running at its most efficient. We are also not talking a difference of 10% efficiency here, so the difference that you've shown (which is correct) isn't actually that much.

System with browser activity = 175W Average

AX860i at 20% load gave me an efficiency of 89.6%, which happens to be 172.2W. So we are looking at 90% efficiency on this unit.
AX1200i at 10% load gave me an efficiency of 84.3%, while at 20% load it gave me an efficiency of 89.2%. If you simply split it we are looking at roughly 87% efficiency on this unit.

Ok, if you compare my actual figures in the reviews against those in the graphs. Mine are actually both lower than what they say they should be at the 20% mark, by 1% at least. So going by the graphs isn't always best. None the less, looking at the figures I just provided. We are looking at a difference of 3% efficiency between the two units, which really isn't that much.

AX860i came in at 38°C ~ 39°C (Corsair Link temp 39.8)
AX1200i came in at 37°C ~ 38°C (Corsair Link temp 38.5)

I used the temp probe on my clamp meter to measure the temperatures above at the exhaust grill of both PSU's with everything else staying consistent. As noted I also confirmed the temps with the Corsair Link software.

TaZZ, you’re the greatest man (REP+), I'm spreading the word about you brother. Had to go ahead and make a decision since the PSU is a birthday gift from the San Francisco ball club. Amazon offered availability of the AX860i Friday as only 1 left in stock; I guess that’s the 1 that’s shipping to me since now they are saying temporarily out of stock. Ok Amazon whatever. Why would they only receive a single unit as their initial stock? These are the questions enthusiasts can never even begin to understand.

This reviewer also cited the AX860i’s fan spinning up at about 30-32%. That’s good news.
http://www.guru3d.com/articles_pages/corsair_ax860i_psu_review,8.html

The the AX860i is on the way along with an H100i from the Corsair Store, so woohoo. Corsair does not present new product lines that often but when they do, I make it Christmas anytime of the year, thanks TaZZ so much, and thanks again George.

Will those Corsair RED individually sleeved cables for the AX860i and AX760i become available soon at the Corsair Store? Those cables are gorgeous!

Something magnificent from Kishi Bashi, perfect for a new build:

http://www.youtube.com/watch?v=A-IJbaNZc9I&feature=related
Edited by MeanBruce - 12/6/12 at 7:58am

George can I use the AX1200i cable kit with the AX860i?Think the cable number is different. If not, when will the AX860i/760i individually sleeved cables become available?

Not sure. I bought a set of the AX650/750/850 cable kits and decided to wait for the funds on the PSU. Now that they are being phased out, I will have to either return them as they were never used, or pay for more wattage than I need since the AX650 is out of stock!