XFX R9 390X or RX480 Nitro for 1440p?

[ShockInfantry]

I was thinking about getting a Sapphire RX480 Nitro to pair along with my new 1440p freesync monitor I ordered, but today I saw on newegg that the XFX 390x is going for about $250 after $30 rebate. Is the 390x still better than incoming RX480 for 1440p?

Another concern is that my current PSU has only 550W (http://www.newegg.com/Product/Product.aspx?Item=N82E16817207013) and it is just about 3 years old now, which is fine when powering my current 7950, but I assume that won't cut it for the 390x if I get it. If I should get the 390x, what PSU should I buy, assuming I am not going to overclock my card or CPU (an i7 3770k)?

 

[Chugalug_]

I am well aware that capacitors wear out over time but you guys still don't get it. You keep thinking that power will hit some kind of maximum. That doesn't happen. It's why we have overpower protection and overcurrent protection. Yes, capacitors failing will increase ripple. But that has nothing to do with "wattage going down". I'd recommend you both read this http://www.jonnyguru.com/forums/showthread.php?t=13311

Not talking about power supplies hitting a maximum.
I'm talking about the power supply eventually becoming extremely unstable at higher wattage due to extensive use above rated speeds which will wear out the capacitors faster.
This essentially makes it unusable at higher wattage due to extreme ripple regardless.
I'm talking about opp eventually becoming less effective over time, this is supported in the forum you just linked me to.
Is this something you can confirm or elaborate on?
"Well if too much current is drawn, you'll get a voltage drop. Draw more current and uvp will kick in. Unless it's a constant current power supply, where if you try draw more, you simply can't."

 

[turkey3_scratch]

Yes unstable at a higher wattage is better terminology. Or in this case, if wattage is decreased, it will reach instability at a lower wattage.

"Well if too much current is drawn, you'll get a voltage drop. Draw more current and uvp will kick in. Unless it's a constant current power supply, where if you try draw more, you simply can't."

That will only happen if:

1) The PSU doesn't burn, which really depends on the design. If everything is overrated to handle an overexcessive amount of current, such as the rectifiers, it may reach this state
2) protections are improperly implemented or overridden.
3) An artificial load is present

Pretty much the only way to get to the power peak and dropoff is using artificial load and overriden protections.

So pretty much it is a near impossible situation where maximum power is reached. 99% of the time it'll burn or shut off before that happens. Anyway, in terms of this guy's load on his computer, it's actually quite less than the 416W on HardOCP. That measurement was taken from the wall, and on Jonnyguru one of the members pointed out that a system with a 390X and 3770K like that should be below 370W. Look at post #6 on here http://www.jonnyguru.com/forums/showthread.php?t=13497

 

[JackNaylorPE]

That's would require a 24 watt average system load with an MSI 390x ..

https://www.techpowerup.com/reviews/MSI/R9_390X_Gaming/28.html

Max instantaneous can break 400 watts

 

[turkey3_scratch]

Instantaneous spikes are not a problem since OCP and OPP values are set far above rated amperages and/or rated wattage. It could be that the MSI 390X is more power hungry. Keep in mind that HardOCP tested with the XFX 390X; there could be a lot of differences in power between the two. Either way, we are talking about the XFX TS 550. Still should be fine. Assuming the caps are all in shape, it should be fine. But we can't really know how his caps are.

 

[atomicWAR]

not really trying to enter this fray again but the fact is a lot more peeps are saying it's not safe to run on that PSU then saying it is safe. (no one seems to say it won't work for sure, just it is a bad idea). That should say a ton about this subject.

 

[turkey3_scratch]

I guarantee if this topic was brought over to JG they'd all say it's fine. I understand the PSU is 3 years old. I already said, it's up to him to replace it or not. We all agree it will work. But we disagree on if it's a good idea or not. That's alright, it is an opinion based matter. If it was me? Not sure what I would do. Considering the age and that it's a group regulated PSU, I'd probably upgrade to a 650W unit (sweet spot of efficiency) and buy a DC-DC unit.

Frankly, if I was him, I'd buy a GTX 1060 and forget all about a new PSU.

 

[JackNaylorPE]

Instantaneous spikes are not a problem since OCP and OPP values are set far above rated amperages and/or rated wattage. It could be that the MSI 390X is more power hungry. Keep in mind that HardOCP tested with the XFX 390X; there could be a lot of differences in power between the two. Either way, we are talking about the XFX TS 550. Still should be fine. Assuming the caps are all in shape, it should be fine. But we can't really know how his caps are.

The instantaneous spikes I wasn't worried about ... it's the 344 watt AVERAGE that causes concern and that's before overclocking. Also that the power limiter on the card can be set to +50%. I was not commenting on the ability of the 550 watt PSU (which is fine if not overclocking anything) ... I was commenting on the ridiculous post on JG saying 370 max draw.

 

[turkey3_scratch]

Instantaneous spikes are not a problem since OCP and OPP values are set far above rated amperages and/or rated wattage. It could be that the MSI 390X is more power hungry. Keep in mind that HardOCP tested with the XFX 390X; there could be a lot of differences in power between the two. Either way, we are talking about the XFX TS 550. Still should be fine. Assuming the caps are all in shape, it should be fine. But we can't really know how his caps are.

The instantaneous spikes I wasn't worried about ... it's the 344 watt AVERAGE that causes concern and that's before overclocking. Also that the power limiter on the card can be set to +50%. I was not commenting on the ability of the 550 watt PSU ... I was commenting on the ridiculous post on JG saying 370 max draw.

So are you implying that HardOCP's data is incorrect? I mean, it is contrary to Techpowerup. But they are two different cards.

 

[JackNaylorPE]

So are you implying that HardOCP's data is incorrect?

I'm not implying anything other than:

1. TPU measured 344 watts, average consumption before overclocking...overclocking was 5.1% ... so I'dd expect at least 10% more draw (378) when overclocked

2. TPU measures the wattage of "only the graphics card via the PCI-Express power connector(s) and PCI-Express bus slot. A Keithley Integra 2700 digital multimeter with 6.5-digit resolution is used for all measurements. Again, the values here only reflect the card's power consumption as measured at its DC inputs, not that of the whole system.

3. HardOCP doesn't do that at merely "estimates" the draw by calculation, TPU is therefore going to be more accurate

4. HardOCP measured the system wattage of the card at 494 watts... It says that going from idle to load takes it from 109 to 494 watts (385 watts)
http://www.hardocp.com/article/2015/06/18/msi_r9_390x_gaming_8g_video_card_review/10

5. HardOCP says that w/o the card, system consumption is 86 watts ... (494-86 = 408 watts)

So all in all TPUs numbers are the more conservative.... and again that's before overclocking or sliding that power limiter up to allow 50% more power.

 

[turkey3_scratch]

The 494W is from the wall, not the DC.

We tested the power utilization at the wall of the entire system.

So it does indeed seem that the XFX 390X is a lot more efficient, seeing as the test setup was quite similar (same CPU).

 

[Karadjgne]

Turkey. Please explain to the good folks here exactly what happens during an instantaneous spike that actually does manage to kick in the OCP or other protective circuitry. To answer the question after that, is why the recommendation is set so high, so that during any possible instantaneous spike, the psu doesn't hit those protections.

 

[ShockInfantry]

However, given that the average fps is just 50 fps, w/ 20% of the games below 30 fps and another 33% are in the 40s, I would proceed as follows....

1. Get a solid AIB RX 480 ... there's a lot of difference between which one you choose ... the Nitro performs alower than the reference cards

The Asus Strix was 6 % faster than the reference card, the MSI Gaming X was 12% faster.


2. Once ya wallet recovers from the 480, grab a 2nd one along with new PSU ... keep in mind that the AIB cards will be drawing close to 200 watts each ...An EVGA B2 750, usually available for about $50-$60, should do just fine.

The other option of course is to wait for the 490

Thanks for the answer Jack! I think I will just get the MSI AIB RX480 whenever it comes out and go from there. Worst case, if I can't stand the drop in graphics quality for FPS, I can just shelve the 1440p monitor for later and keep using my current 1080p monitor (and psu) a little longer. Heard speculation that RX 490 is probably just dual 480 with better memory bus so not too terribly excited for it, but can't hurt to keep my eyes on it.

 

[JackNaylorPE]

The 494W is from the wall, not the DC.

So it does indeed seem that the XFX 390X is a lot more efficient, seeing as the test setup was quite similar (same CPU).

So ... then you just take the net 408 volts, multiply 85% PSU efficiency and we get .... 346 watts, within 2 watts of TPU

You can only say it's more efficient if it is delivering the same results. Delivering more fps always costs more power.... and it's not linear.

XFX 390x garnered an avg fps of 43.8 with it's 284 watts (6.49 watts per fps)
MSI 390x garnered an avg fps of 49.9 with its 346 watts (6.93 watts per fps)

But they overclocked the XFX and that took it up to 551 watts (551-82 = 469 watts x 0.85 =) 399 watts for the XFX card overclocked. That alone is more than Post No. 6.

Here's some comparisons with the much more efficient 480s

Refence 480 draws 163 watts / 37.7 fps in W3 / 77fps in BF3 OCd (2.12 watts per fps)
Asus 480 draws 177 watts / 40.3 fps in W3 / 79.0 in BF3 OCd (2.24 watts per fps)
MSI 480 draws 196 / 41.3 in Witcher 3 / 83.6 fps in BF3 OCd (2.34 watts per fps)

Just like anything else in the PC case ... getting more oomph out of anything requires more power ... and the more power oomph ya chase, the power increases exponentially.

But still... if the OP doesn't OC and stays within the "out of box" envelopes discussed (344 Card + 90 CPU + 30 MoBo + 40 all else), his 550W PSU will have at least 10% to spare.

 

[ShockInfantry]

So an update on this is that I ended up finding a Sapphire Nitro Fury 11247-03-40G for $310 and with the current elevated pricing and unavailability for AIB RX480 and 1060, I figure I might as well pony up some extra dollars to get the Fury at that price.

 

[Karadjgne]

Bye bye 1080p lol. Fury will do well on 1440p