PowerColor 7870 MYST Edition (Tahiti LE) Review

[Daveburt714]

I hesitate to call this a review because I'm no expert, but I couldn't think of a better title... So consider it first impressions.
This is the card I picked up yesterday:
http://www.microcenter.com/product/4...ion_Video_Card

Even though I'm not a big gamer the "NeverSettle-Reloaded" bundle was just too hard to pass up and the card didn't disappoint!
Here's some info and results (all tests @ ambient of ~23c):

I did some initial testing (out of the box/stock cooling), and idle temps were ~34c. Using a 3 minute run of Furmark temps shot up to 78c and the fan got a little loud (not obnoxious), but noticeable and the temps were a little high for my taste. So I decided to take the Zalman VF3000 off my old 6870 and put it on this new card.

Here's some pics of the card disassembled:

The HSF had direct contact heat pipes, but the fan was centered over the GPU with no airflow over the pipes...
I'm sure there's a mod in there to make this a NICE cooler!


Here's a shot of the GPU:


Sorry for the following pic but the flash blew things out, my camera's wimpy and my hands aren't steady enough for flashless pics...
Anyway, the card seems to have some decent Hynix DDR5 memory modules onboard:


After the installation of the aftermarket cooler and some ram sinks on the memory chips (they were bare at stock) I decided to see what this card could do...
I'm pretty happy with the results! Using the same tests after the mods the idle temp was 27c and the load temp was 52c after 3 minutes of Furmark.
The fans on the VF3000 were set @ 1800 RPM which is almost silent.

For some reason Afterburner won't allow me to adjust v's, so these clocks were done at stock voltages...
Final (stable) results were 1215 GPU/1650 Mem @ stock voltage and no artifacts! If I had voltage adjustment I could probably push them higher so I stuck with clean runs...


PassMark 3D:


I'm sure the GTX 680 has OC headroom, but it's also a $500 card... In that sense this 7870 is looking pretty good to me...

It's been a long time since I ran Unigine Heaven benchmark, but I DL'd the newest version (4.0) and ran it on this new card tonight.
I may have messed it up because my monitor is 1920x1200 so I ran it "windowed" @ 1920x1080. I did run it at extreme though, so here are the results:

[TEDY]

pics of with mounted zf3000 and all? zf3000 is more gfx or proc?

how much was it?

http://www.zalman.com/global/product...ad.php?Idx=385

[Daveburt714]

Sorry TEDY, I was anxious to to try the card out and didn't take any pics of the cooler installed on the 7870...

It fits exactly the same as it did on the 6870 though. The one drawback is that it does add another 3/4" to the length of the card and may be a problem on smaller cases.
Here's a link to the 6870 thread with pics of the cooler installed, it fits exactly the same on the 7870:
http://www.xtremesystems.org/forums/...ler&highlight=

[TEDY]

thanks.

[BeepBeep2]

Thanks Dave.
This is a 1536 shader card correct?
Is voltage locked with MSI AB? Bummer... does GPU-Z report the voltage?

[Daveburt714]

Yeah, it's the 1536 SP card Sam...

Voltage is locked in AB, but Trixx (seems) to allow voltage adjustment.
I say seems because I can see improvements in benchmarks and bumping the v's was good for an extra 10 mhz (stable), but going past 1.2v didn't offer any more in the way of clocks. I still have more testing to do but I get the feeling that may be all the chip has in it (still, not too shabby though ) ...

The "Sensor Tab" on GPU-z isn't reporting correctly on voltages or clocks. I can see results when running benchmarks but the changes shown in sensors doesn't reflect the changes I'm seeing in tests...

Here's a ss with Furmark running and GPU-z tabs opened. Temps are a bit higher due to a number of factors (ambient temps/closed case/bump in Vcore):



NOTE: I also just noticed that Furmark is reporting the wrong clocks when GPU-z is open!
When running it without GPU-z it reports the same clocks as Trixx and AB, so something is a little wonky in the reporting...

[Daveburt714]

Just wanted to post a correction...
After talking to the folks over at TechPowerup I found out why GPU-z seemed weird to me.

There's no problem with it's reporting it was just my own noobishness at clocking video cards.
After adjusting powerboost in ccc to +20% GPU-z reports the clocks holding. So, in reality the card was throttling the clocks back under Furmark...

[Ket]

I do like the Tahiti LE, you need +200MHz or so on the core to match 7950 performance but considering the chasm of cash you save the Tahiti LEis a far better option than the 7950 IMO, the extra 1GB vRAM of the 7950 is nice especially if running skyrim graphics mods but its not essential. Have you done anything with the VRM cooling? Some tweaks there can really get VRM temps down. On my 7950 I got VRM temps from 100c or so way down to about 72-80c (measured with a infrared temp gun). I also want to see more sexy pics of your card

[Daveburt714]

Have you done anything with the VRM cooling? Some tweaks there can really get VRM temps down. On my 7950 I got VRM temps from 100c or so way down to about 72-80c (measured with a infrared temp gun). I also want to see more sexy pics of your card

Yeah, I really like this card Ket. Nice boost over the 6870...

After figuring out what was going on with the throttling I noticed my VRM temps were getting way too high!
During a Furmark run they hit 112c @ 1.2v (1225/1650)...
I'm sure Furmark pushes the card further than any real world use would, but those temps were a little scary...

I didn't take any pics, but I did pull the card last night to try and help the VRM temps (with limited success (dropped ~10c)).
I'm not very experienced with video cards, but the VRM's looked odd compared to mobo power sections...
They were really small (4 sets of 2, one larger than the other) and they were covered with small metal heatspreaders. Digital maybe?

Here's a pic of the sink that was on them, I replaced it with the ram sinks hoping the extra surface area would help:



The one bad thing about the pcb layout is that there are a number of caps right next to the vrm's, so there's not alot of room to work with...
The actual pcb looks pretty sparse compared to the 6870, but the performance is a nice step up!

I'm sure I'll wind up pulling it again, next time I'll take more pics!

BTW: If you could show me what you did with the vrm cooling on your 7950 it might give me some ideas...

[Ket]

Heres a pic of what I did to the VRMs on my 7950;



Note the massive heatsink near the vBIOS switch, theres VRMs under there too that with stock cooling had nothing better than... wait for it... tadaa a measly metal arm that formed part of the anti-warp bar covering the VRMs with a crap thermal pad underneath, so a 0/10 for design and thermodynamic sense for Sapphire there. If your VRMs look like mine do in the pic they are digital VRMs, typically digital VRMs get WAY hotter than analog VRMs do. I really don't understand why digital VRMs are used sometimes older tech is better and thats very much the case for analog VRMs. Anyway, for the VRMs at the back of the card I actually ended up chopping the VRM heatsink up so it looks like your VRM heatsink. The stock heatsink on my card had a lot of surface area but due to the resistors which somebody at Sapphire clearly failed to take into account the VRM heatsink was "raised" with a dirty thick 3mm or so thermal pad. As you can probably imagine, such a poor "fix" for the blunder Sapphire made lead to extremely poor contact and temps. I used my Dremel to sand away the metal standoffs of the VRM heatsink and chopped off the part of the heatsink that was preventing it from making a solid contact with the VRMs. For good measure I then slapped a Gelid Icy Vision A on my card which is so vastly superior to the Vapor-X cooler in every way words can't describe it.

From the look of your stock VRM heatsink its actually good (I wish the stock heatsink for my 7950 was like yours, would of made my modding life much easier) you should see big improvements if you replace the pushpins with a few screws and nuts (make sure you don't over tighten them and warp the PCB) and replace the thermal pad with a 0.5mm Phobya XT 7w/km thermal pad. Thats about all you can do to cool the over enthusiastic digital VRMs, unless you can find a second VRM heatsink then you can mount it to the back of the card using slightly longer screws that come up enough to allow you to secure both front and back heatsinks in place using the existing mounting holes.

Make sure you take lots of pics when you next pull out your card too

[Daveburt714]

OK, mini necro with a bunch of pics...

First off, I'm decent at OC'ing things but this whole experience taught me that video cards aren't the same beasts as CPU's!
I pulled the card again tonight to try and solve the vrm temp problems. I used Ket's suggestion, removed the plastic clips and replaced them with screws.
This card has digital VRM's that run REALLY hot (>100c when oc'd).

I quickly figured out that Furmark pushes video cards to the limit. It's kind of like P95 for GPU's, you'll never actually see that kind of stress during real world use...

Anyway, here's a bunch of pics:

The full card naked (pretty sparsely populated IMO):


Close-up's of the power section. I was trying to get pics where you could read the numbers (without much success):



The heatsink wasn't completely flat, so I manipulated it until it was and then re-installed it using screws instead of the plastic clips...


VRM temps went down a little using Furmark, but were still close to 100c... At this point I decided to quit using Furmark for stress testing, and went to Heaven (4.0).
It seems to be more realistic for daily use, it's been very solid for gaming and doesn't stress the power section as much!

Trixx has been the best OC'ing software for this card and setting CCC PowerBoost to +20% has helped too!

Anyway, here's a pic of the card fully assembled with the Zalman VF3000 cooler:


After all these mods and tweaking here's my new Heaven score (while running GPU-z in the background), with a SS of max vrm temps during the proccess:



For the price this Tahiti LE card has made me pretty happy!

[screwtech02]

Be nice if someone were to review these in a eyefinity res/setup. Noone has done such a review on the 7870's since release from what I have seen...

[ah_khoo]

nice card, using one for myself too. was having throttling issue till i flashed d newer BIOS into it. oc mileage is good (considering the stock clock) for undervolt oc. hit 1050 core/1500 mem w/o much issue. with better cooling d card will fly...

[Daveburt714]

Well, this is a sad situation... This card has failed!

I pushed it a little and made a few mods, but never went crazy with voltage or anything...
The sad thing is, I was done tuning it and was happy with the results. Then a month later this (crappy pic but you get the idea):


It did this on my main rig (even in bios) so I swapped it out for my old 6870 and everything was fine.
This pic is of the card installed on my new gear (6600k/ASRock EX6) that's on the bench getting ready to be my new server.
I'm no expert, but it looks like a Vram failure to me.

This is my first PowerColor card, so I have no idea what their RMA policy is (OFC I'll return it to stock 1st).
I'm not the type of person to abuse something and then expect a replacement, but I feel justified in trying an RMA in this situation...

[Sadhana]

Any update about the RMA process for failure Powercolor Myst Ed.? Iam getting the Saphire Tahiti LE and recently oc to 1100/1600 with stock voltage using Saphire Trixx and aware about the availability of similar Tahiti LE based cards in my country. Don't want to messed my card because the lack of supply in the market.

[Ket]

OK, mini necro with a bunch of pics...

First off, I'm decent at OC'ing things but this whole experience taught me that video cards aren't the same beasts as CPU's!
I pulled the card again tonight to try and solve the vrm temp problems. I used Ket's suggestion, removed the plastic clips and replaced them with screws.
This card has digital VRM's that run REALLY hot (>100c when oc'd).

I quickly figured out that Furmark pushes video cards to the limit. It's kind of like P95 for GPU's, you'll never actually see that kind of stress during real world use...

Anyway, here's a bunch of pics:

The full card naked (pretty sparsely populated IMO):


Close-up's of the power section. I was trying to get pics where you could read the numbers (without much success):



The heatsink wasn't completely flat, so I manipulated it until it was and then re-installed it using screws instead of the plastic clips...


VRM temps went down a little using Furmark, but were still close to 100c... At this point I decided to quit using Furmark for stress testing, and went to Heaven (4.0).
It seems to be more realistic for daily use, it's been very solid for gaming and doesn't stress the power section as much!

Trixx has been the best OC'ing software for this card and setting CCC PowerBoost to +20% has helped too!

Anyway, here's a pic of the card fully assembled with the Zalman VF3000 cooler:


After all these mods and tweaking here's my new Heaven score (while running GPU-z in the background), with a SS of max vrm temps during the proccess:



For the price this Tahiti LE card has made me pretty happy!

Well, this is a sad situation... This card has failed!

I pushed it a little and made a few mods, but never went crazy with voltage or anything...
The sad thing is, I was done tuning it and was happy with the results. Then a month later this (crappy pic but you get the idea):


It did this on my main rig (even in bios) so I swapped it out for my old 6870 and everything was fine.
This pic is of the card installed on my new gear (6600k/ASRock EX6) that's on the bench getting ready to be my new server.
I'm no expert, but it looks like a Vram failure to me.

This is my first PowerColor card, so I have no idea what their RMA policy is (OFC I'll return it to stock 1st).
I'm not the type of person to abuse something and then expect a replacement, but I feel justified in trying an RMA in this situation...

Nice pics, that thermal pad looks pretty crappy though... a Phobya 7w pad will definitely help you out there, VRM temps will likely drop around 5c, which for VRMs is a lot. Some things to note though, that reading for MVDDC is VERY odd, it should be reading 1.500 - 1.600, something in that area. Considering you don't have many VRMs or phases on that card I'd think 1.19v may be a little much for it backing it down to 1.15v would be wise. Also, don't use Trixx if you can help it that thing does some weird stuff to voltages when I used that software I saw it causing brief GPU voltage spikes up to 1.498v. As for your card dying like it has, I haven't seen red stripes for bad memory before usually green, sometimes purple, so maybe the GPU itself developed a fault. Probably caused by Trixx causing those weird GPU spikes I mentioned.

Something which I have learned about the digital VRMs these Tahiti / LE based cards use is that you can keep them super cool by doing a little vBIOS Hex editing. For me I can set voltage to 1.056v and then increase the VRM signal to 126 (1.093v). Under normal load the voltage is pretty much bang on 1.056v and under extreme heavy load its 1.004v minimum. Doing this even with the hot weather in the UK atm (its 30c+) the VRMs don't get much beyond 80c with my Gelid Icy Vison if I take the side panel off (got plans for modding the Gelid, don't want to take the side panel off every time its hot). As some may wonder, no don't simply set 1.093v with a VRM signal of 126, for some reason doing so will turn your VRMs into mini blast furnaces (100c - 110c). Ample airflow over the VRMs is also extremely important to keep these VRMs cool, I stuck a fan next to them in conditions where they were reaching 100c+ and they did not exceed 72c. Be warned while using this voltage and VRM signaling trick quite drastically reduces VRM temps under extreme loads that at least Trixx is pretty dumb, initially it will read the VRM signal, in my case 126, then if you hit the reset button it'll start reading the voltage value. Just another reason why I wouldn't trust Trixx as far as I could throw it its a buggy POS.

I have to say unless AMD start using quality VRMs to reduce the ridiculous and copious amounts of heat generated when a card is under full load I'll likely be going back to nvidia sooner rather than later. I'm having to mod my Gelid with 2x Arctic F9s in order to reign in the VRM temps I've reduced them as much as I can through vBIOS mods and heatsink mods.

[Daveburt714]

Any update about the RMA process for failure Powercolor Myst Ed.? Iam getting the Saphire Tahiti LE and recently oc to 1100/1600 with stock voltage using Saphire Trixx and aware about the availability of similar Tahiti LE based cards in my country. Don't want to messed my card because the lack of supply in the market.

Another Necro...

PowerColor was decent on the RMA. From the time they received it, to the time they tested and shipped it back was ~12 business days.
So from the time I shipped it, back to my doorstep was ~3 weeks. FedEx ground from Ohio to California both ways...

I haven't tested it yet, but it's not the same card (different serial#).
I didn't abuse the last card, but I'll be very gentle this time.
Just wouldn't seem right not to OC it though!

Anyway... I'm about to swap the coolers again and I had a question.
Since VRM temps seemed to be the biggest problem on the last card, is it safe to ditch the thermal pad on the VRM's for MX4?
It's non-conductive so I think it'll be OK, just wanted a 2nd opinion...

[STEvil]

VRM sinks dont usually sit flat on all of the VRM components, so using a paste instead of a pad is generally a bad idea if the VRM sink covers more than 2 components..

[Daveburt714]

VRM sinks dont usually sit flat on all of the VRM components, so using a paste instead of a pad is generally a bad idea if the VRM sink covers more than 2 components..

Thanks man! I took that in to consideration, and made sure the sink was flat (glass trick), it wasn't, so I fixed it...
I also went back to the plastic pins, used MX-4 and ditched the screws. So far it seems to be working pretty well.
The highest temps I've seen so far on the VRM's is ~85c under "Furmark". That's WAY better than the +100c temps I was seeing with the last card!
I get the feeling my initial card had some problems from the start compared to what I'm seeing with this one...

This 7870 Myst still OC's quite well, but I'm gonna be real gentle this time...