Observation and questions about my new R9-390

[CuriousMike]

Per http://forums.anandtech.com/showthread.php?t=2468067, I just received my new Sapphire Nitro Radeon R9 390. I was worried about power and size, and size isn't an issue in my Fractal Design Mini - removing the middle drive bay gave me plenty o' space.

Observations using Dirt Rally as it's my current addiction

Using a kill-o-watt
i5-4590
Corsair RM 550w p/s
2560x1440, 4x MSAA, Preset Ultra

GTX 950 averaged about 140 watts during the benchmark

FPS min/avg/max = 27/32/43 total frames = 6614 frames rendered

R9 390 averaged about 365w peaking at 395 watts
FPS min/avg/max = 62/74/91 = 15302 frames rendered

Questions
1. Max of 395 watts seems totally safe for my p/s, right? I understand a more demanding game might pull more, but I assume 400w is ballparking it?

2 a) For Dirt Rally, I turned ON vsync, and power dropped to 310w, peaking to 349 saving close to 50w on average. However, the game reported min/avg/max = 51/59/60 - so I actually fell below 60fps with Vsynch on at some point, even though with it off I never did. This is possible?
b) Is it possible to "undervolt" the card to save some watts? If so, is there a balance between saving watts and lost frames? i.e., is it possible to undervolt it so I save 20w on average, and lose "only" 3-5 fps ?

 

[thesmokingman]

Oh, duh I missed the killwatt. At 395w you are still very safe man. Don't even bother worrying about it.

 

[raghu78]

Undervolting might affect stability depending on the chip you have. You are safe at 400w. Your PSU is very high quality and can easily handle 550w on +12v rail. Don't sweat it

http://www.corsair.com/en-us/rm-series-rm550-80-plus-gold-certified-power-supply

 

[Silverforce11]

Use afterburner and set the vcore to -25mV to start, then test it in games/benches. If it's stable, set to -37mV and try again. Some samples are stable at -50mV and that's when you really save a lot of power.

With Crimson, don't use vsync but use the Frame Rate Target option. It's a smooth frame rate limiter. In-game, disable vsync.

 

[happy medium]

The only problem I can forsee is if your ever gonna upgrade/overclock your cpu?
Your cpu pulls 84 watts now,I would imagine a 4970k overclocked pulls much more wattage.

I read somewhere that when a 390 uses Async compute , your wattage actually goes up about 40 watts also. I would be carefull.

 

[Erithan13]

Power supplies are rated for the system draw, you'll measure somewhat more at the wall due to PSU inefficiency. If you're seeing 400W at the wall that would equate to 340W system draw at 85% PSU efficiency for example. That sort of load on a quality 550W PSU will be absolutely no problem whatsoever, nothing to worry about.

 

[AtenRa]

Try fps cap on the driver (crimson), it may be better than vsync.

 

[Kenmitch]

I wouldn't worry about it.

My current rig:
4790k 4.4GHz
390 crossfire Stock clocks with a 37mV undervolt. <- Helps with temps.
EVGA SuperNova 750w
16GB DDR3
1TB of SSD's

Roughly guessing I've got about 100w of safety cushion.

 

[CuriousMike]

With Crimson, don't use vsync but use the Frame Rate Target option. It's a smooth frame rate limiter. In-game, disable vsync.

Try fps cap on the driver (crimson), it may be better than vsync.

Thanks everyone for the clarifications and suggestions.
Sounds like I'll leave it be, and I'll try the "Frame Rate Target" (hoping that it handle screen tearing.)

 

[Silverforce11]

Thanks everyone for the clarifications and suggestions.
Sounds like I'll leave it be, and I'll try the "Frame Rate Target" (hoping that it handle screen tearing.)

When you use it, I know some folks use 1hz below their monitor refresh rate to avoid tearing. But for me, it works at 60fps/60hz in my current games.

 

[MTDEW]

And most newer titles have a Borderless Window option that usually helps eliminate tearing with v-sync off also.

 

[someEEguy]

Per http://forums.anandtech.com/showthread.php?t=2468067, I just received my new Sapphire Nitro Radeon R9 390. I was worried about power and size, and size isn't an issue in my Fractal Design Mini - removing the middle drive bay gave me plenty o' space.

Observations using Dirt Rally as it's my current addiction

Using a kill-o-watt
i5-4590
Corsair RM 550w p/s
2560x1440, 4x MSAA, Preset Ultra

GTX 950 averaged about 140 watts during the benchmark

FPS min/avg/max = 27/32/43 total frames = 6614 frames rendered

R9 390 averaged about 365w peaking at 395 watts
FPS min/avg/max = 62/74/91 = 15302 frames rendered

Questions
1. Max of 395 watts seems totally safe for my p/s, right? I understand a more demanding game might pull more, but I assume 400w is ballparking it?

To put things into context, your kill-o-watt is measuring what is marked "Input Watts" on this chart for your power supply. Meaning you should not worry unless your kill-o-watt readings start approaching ~600 watts.

 

[Madpacket]

This may give you comfort. One of my gaming rigs is an ITX based Silverstone Fortress running an MSI 390 (the MSI's are the most power hungry of the 390's) a stock clocked 4790K, AsRock Z97 WiFi enabled that likes to keep the CPU turbo'd, 16GB DDR3, Dual 480GB AMD Radeon SSD's (raid stripe) and 3 120mm fans.

I'm running all the above on a Silverstone SFX-500W-L power supply. I have zero power related issues even with my Killawatt showing up to 450W spikes.

I wouldn't worry about stability but these 390's are severely overvolted so you should be able to claw back 50-75W pretty easily using Afterburner or Trixx.

I should also add I'm using a Freesync monitor where I cap max FPS to 90hz when enabled. Even disabled with games like BF4 hitting 144Hz in spots there's no issues power wise.

 

[Shmee]

Congrats on the new card! The nitro/tri X design is top notch.

 

[ultima_trev]

I run -31 mv on the vcore and -30% on power limit in Afterburner. I may lose 3-5 frames per second in some situations (still talking well over 75 frames anyway) but it runs so much cooler and quieter that it's worth it.

 

[Rvenger]

I ran a 290 on a 450watt and it worked fine. You're fine.

 

[parkerface]

Grats on your new card! I have a very similar setup and an avid Dirt Rally player so maybe I can add a few data points or answer some unasked questions. I'm using an MSI R9 390, 4670k@4.6ghz.

Playing at 1440p, 4xMSAA, and ultra preset my 390 at stock settings saw similar numbers to yours:

410w system draw (diff cpu with an overclock, again)
15168 frames, 60min/74avg/101max

Stock with +50% power limit:

420w system draw
(missed framecount), 60min/76avg/106max

I mimicked ultima_trev's undervolt scenario as well (stock clocks, -31mv core, -30% power limit):

380w system draw
15159 frames, 59min/74avg/101max Almost identical to stock results with less power draw.

My card overclock of 1175core and 1700vram, +50mv +50% power limit:

515w system draw
17612 frames, 68min/86avg/118max

With that said, I do run this game with vsync enabled. Dirt Rally does not have a borderless window option, and using the Framerate Target Control feature in the Crimson software leaves me with either screen tearing at 60-62fps, or distracting little hitches when using 59fps. I would not even call them stutters really, just something noticeable when the scenery shifts laterally very fast in a turn that I don't get when using vsync.

I hope some of this is relevant to you. Enjoy.

 

[CuriousMike]

With that said, I do run this game with vsync enabled. Dirt Rally does not have a borderless window option, and using the Framerate Target Control feature in the Crimson software leaves me with either screen tearing at 60-62fps, or distracting little hitches when using 59fps. I would not even call them stutters really, just something noticeable when the scenery shifts laterally very fast in a turn that I don't get when using vsync.

I hope some of this is relevant to you. Enjoy.

Thanks for your input. I've noticed that the game feels.... weird.... when it isn't at 60fps.
I noticed this on my GTX 950, and again with the 390. It's a hitchiness that almost feels like I'm running at 20fps... but I could be at (for example) 54fps.

 

[parkerface]

I've noticed that the game feels.... weird.... when it isn't at 60fps.

I agree. I don't know enough to be able to distinguish between data being streamed in the background, if its a car physics + rendering sync wait, or even my own nonsense, but anything under 60 in this game to me is not just a low framerate sensation.

Maybe it's something else entirely. :ninja:

 

[CuriousMike]

Somewhat random update.

I ended up making a sideways move into a RX480 4GB, running at 1320/2000.

R9 390 averaged about 365w peaking at 395 watts
FPS min/avg/max = 62/74/91 = 15302 frames rendered

RX 480 averaged about 238w peaking at 248 watts.
FPS min/avg/max = 54/65/82 = 13450 frames rendered

So, while the power use dropped > 120W on average, for this particular game, I lost 8-10 frames on average.