# Radeon HD 7870 "Tahiti LE" Can Pair with HD 7900 Series in CrossFireX



## btarunr (Dec 7, 2012)

While testing Club 3D Radeon HD 7870 jokerCard, one of the three Radeon HD 7870 "Tahiti LE" graphics cards you can buy, we discovered that it can pair with Radeon HD 7900 series cards in CrossFireX. Our VGA testing lab, which has battened down the hatches for winter (lack of VGA launches), spent a lot of time toying with Club 3D's card and while brainstorming for the review's conclusion, it came up that HD 7870 Tahiti LE is "bad" because it can't pair with common HD 7870 or HD 7850 "Pitcairn" graphics cards. A bulb supernova just went off over our heads: "...sure Tahiti LE won't pair with Pitcairn, but will it pair with HD 7900 series "Tahiti", which have more stream processors, and more memory?" The answer turned out to be yes!

We successfully managed to pair the Club 3D HD 7870 jokerCard with a Radeon HD 7950 and HD 7970 (reference). We casually put it through 3DMark 11 and Sleeping Dogs, and found the contraptions to scale fairly well. We noticed some micro-stutter in 3DMark 11, but Sleeping Dogs felt smooth. This could be great news for current HD 7900 series owners who can upgrade to CrossFire for a modest $249~269. We even tried our luck at unlocking disabled shaders (stream processors), which didn't work. AMD used the mod-proof fuses method to lock the shaders. Check out our Club 3D HD 7870 jokerCard review.



 



*View at TechPowerUp Main Site*


----------



## RCoon (Dec 7, 2012)

Of course it will pair with the 7900 series, its essentially a sucky 7950 anyway right?


----------



## brandonwh64 (Dec 7, 2012)

Hmmm this has me thinking that the LE can be unlocked some how with shader count...


----------



## btarunr (Dec 7, 2012)

RCoon said:


> Of course it will pair with the 7900 series, its essentially a sucky 7950 anyway right?



Normally, we'd think it shouldn't because memory amount/bus/ lack of parity. Hence the excitement.



brandonwh64 said:


> Hmmm this has me thinking that the LE can be unlocked some how with shader count...



W1zzard is working on that.


----------



## RCoon (Dec 7, 2012)

btarunr said:


> Normally, we'd think it shouldn't because memory amount/bus/ lack of parity. Hence the excitement.
> 
> 
> 
> W1zzard is working on that.



I see, in which case i look forward to seeing people buy two 7870LE's and crossfiring them at 7950 speeds for a substantially low cost xD


----------



## btarunr (Dec 7, 2012)

RCoon said:


> I see, in which case i look forward to seeing people buy two 7870LE's and crossfiring them at 7950 speeds for a substantially low cost xD



Exactly.


----------



## RCoon (Dec 7, 2012)

btarunr said:


> Exactly.



Can you give us a sneaky bit of info on how the cooler performs? EDIT: when it's in that crossfire


----------



## m1dg3t (Dec 7, 2012)

Pretty cool! Nice going there W1zz


----------



## btarunr (Dec 7, 2012)

RCoon said:


> Can you give us a sneaky bit of info on how the cooler performs? EDIT: when it's in that crossfire



Haven't done testing with that crossfire setup, but it's far from being the quietest card in its class.


----------



## INSTG8R (Dec 7, 2012)

Interesting. Very keen on seeing the results. Might even make me dip my toe back into the water with Crossfire(Last time was WAYYY back with X1900XT's) If they scale well seems like a great deal.

Not keen on using Club3D, wonder if Sapphire is gonna do any Tahiti LE's.


----------



## btarunr (Dec 7, 2012)

INSTG8R said:


> Interesting. Very keen on seeing the results. Might even make me dip my toe back into the water with Crossfire(Last time was WAYYY back with X1900XT's) If they scale well seems like a great deal.
> 
> Not keen on using Club3D, wonder if Sapphire is gonna do any Tahiti LE's.



Sapphire won't do a Tahiti LE. They hate it. The only other brands are PowerColor (HD 7870 Myst) and VTX3D, and those cards are virtually identical to Club3D's card, since they're made on the same exact production line (TUL).


----------



## cadaveca (Dec 7, 2012)

I was hoping for a GTO model. 


Still, good info, can't wait for the review!


----------



## btarunr (Dec 7, 2012)

cadaveca said:


> can't wait for the review!



_You_ don't have to


----------



## cadaveca (Dec 7, 2012)

btarunr said:


> _You_ don't have to







BTA>>>ME








I like to wait anyway. I mean, you already know I'm a bit off-kilter...


----------



## Frick (Dec 7, 2012)

cadaveca said:


> I was hoping for a GTO model.
> 
> 
> Still, good info, can't wait for the review!



That would have been nice. GTO + unlocks would be awesome.


----------



## Socram13 (Dec 7, 2012)

I´m waiting for that 7870 LE review for some weeks, hope that it manages to be on pair with GTX 660 Ti.


----------



## 3870x2 (Dec 7, 2012)

Can the 7950 be unlocked to 7970?  Sorry for the ignorance, I haven't done my homework.


----------



## W1zzard (Dec 7, 2012)

3870x2 said:


> Can the 7950 be unlocked to 7970?  Sorry for the ignorance, I haven't done my homework.



No. there are no shader unlocks for HD 7000 Series


----------



## Widjaja (Dec 7, 2012)

Will be interesting to see the review for this card.


----------



## W1zzard (Dec 7, 2012)

Widjaja said:


> Will be interesting to see the review for this card.



review is up: http://www.techpowerup.com/reviews/Club_3D/HD_7870_jokerCard_Tahiti_LE/


----------



## m1dg3t (Dec 7, 2012)

W1zzard said:


> No. there are no shader unlocks for HD 7000 Series



The stop gaps are on the silicone level?

 For example, the 7950 I have, is identical physically in appearance to a referrence 7970 but there is no chance of getting it to function as such?


----------



## cadaveca (Dec 7, 2012)

m1dg3t said:


> The stop gaps are on the silicone level?
> 
> For example, the 7950 I have, is identical physically in appearance to a referrence 7970 but there is no chance of getting it to function as such?



Nope. I'm running a 7970 BIOS anyway, makes ZERO difference, except in "stock" clocks and voltages.

I kinda thought maybe they hid some PCB bridge under the metal ring that goes around the core or something, but getting that off isn't going to be very easy. It really does seem as though there are actual physical disabling of the core, and how or where is not easily found.


----------



## W1zzard (Dec 7, 2012)

There are fuses inside the die that can be blown in the late production process. This is a permanent change.


----------



## WarEagleAU (Dec 8, 2012)

IF W1zzard manages to unlock the cores and what have you, what essentially brought me to TPU back in 2006 the Radeon unlocking of an X850, will be huge. I would definitely upgrade my 6870 to a 7870 LE no problem


----------



## T4C Fantasy (Dec 8, 2012)

did anyone notice tahiti LE is a cayman substrant clone?  looks just like the 1536 core hd6970 chip, i know how amd cheapened costs here ^^

http://www.techpowerup.com/gpudb/1860/AMD_Radeon_HD_7870_XT.html

http://www.techpowerup.com/gpudb/258/AMD_Radeon_HD_6970_(PCIe_2.0_x16).html


----------



## INSTG8R (Dec 8, 2012)

btarunr said:


> Sapphire won't do a Tahiti LE. They hate it. The only other brands are PowerColor (HD 7870 Myst) and VTX3D, and those cards are virtually identical to Club3D's card, since they're made on the same exact production line (TUL).



I will chock that up to Sapphires level of quality that they have taken a pass on these 



WarEagleAU said:


> IF W1zzard manages to unlock the cores and what have you, what essentially brought me to TPU back in 2006 the Radeon unlocking of an X850, will be huge. I would definitely upgrade my 6870 to a 7870 LE no problem



Hehe! "Young Fella"  I ended up here looking for info on how to unlock my 9800 Pro to XT. I was completely successful and became a bit of a "guru" on the "Can I unlock mine?" and I never left  (BTW it was a Sapphire and my still standing loyalty thru every Gen since)


----------



## blibba (Dec 8, 2012)

Nobody will be unlocking any HD68** or HD7*** chips - it's impossible, as clearly stated by Wizz above.

I'd be interested to see how 7950+7930 performs in CF vs. 2*7950.

(Yeah, I just called it a 7930 )


----------



## Ferrum Master (Dec 8, 2012)

Nice I just ordered a 7970 at last, going to ditch the green camp, Huang had too much of my money lately, need to support AMD just for the sake of the competition.

So after cracking hours of tech reviews and RMA rates... NO SAPPHIRES OR GIGABYTES. Those cheapskates uses poor components that result in abnormalities, like ringing inductors at load and poor OC with artifacts... ASUS, MSI and some others frankly doesn't suffer from it at such rates. Myself I took the OEM one, because of the turbine solution only.


----------



## T4C Fantasy (Dec 8, 2012)

Ferrum Master said:


> Nice I just ordered a 7970 at last, going to ditch the green camp, Huang had too much of my money lately, need to support AMD just for the sake of the competition.
> 
> So after cracking hours of tech reviews and RMA rates... NO SAPPHIRES OR GIGABYTES. Those cheapskates uses poor components that result in abnormalities, like ringing inductors at load and poor OC with artifacts... ASUS, MSI and some others frankly doesn't suffer from it at such rates. Myself I took the OEM one, because of the turbine solution only.



check out tpus database for card stats like length, and performance figures ^^i think every hd7970 is in there if not tell me

http://www.techpowerup.com/gpudb/296/AMD_Radeon_HD_7970.html

http://www.techpowerup.com/gpudb/365/AMD_Radeon_HD_7970_GHz_Edition_(PCIe_3.0_x16).html


----------



## Ferrum Master (Dec 8, 2012)

T4C Fantasy said:


> check out tpus database for card stats like length, and performance figures ^^i think every hd7970 is in there if not tell me
> 
> http://www.techpowerup.com/gpudb/296/AMD_Radeon_HD_7970.html
> 
> http://www.techpowerup.com/gpudb/365/AMD_Radeon_HD_7970_GHz_Edition_(PCIe_3.0_x16).html



Aww those inches... TPU could be more democratic and add metric system option


----------



## TheGuruStud (Dec 8, 2012)

ferrum master said:


> aww those inches... Tpu could be more democratic and add metric system option



commie!


----------



## Frick (Dec 8, 2012)

Ferrum Master said:


> Aww those inches... TPU could be more democratic and add metric system option



But it says mm under inches.


----------



## T4C Fantasy (Dec 8, 2012)

Ferrum Master said:


> Aww those inches... TPU could be more democratic and add metric system option



yes its already in, just click on the card and it shows mm right under inches


----------



## Ferrum Master (Dec 8, 2012)

TheGuruStud said:


> commie!



Don't even try to pull that question up even as a joke for my countrymen, do some history studies... .



T4C Fantasy said:


> yes its already in, just click on the card and it shows mm right under inches



Yeah I noticed that now, thanks. I was just looking in the other Other Changes section, where the imperial numbers where only present , there for I took it as default.


----------



## BallackCFC (Feb 19, 2013)

Has anyone tried to crossfire a 7870 tahiti LE with a 7970? I purchased the 7870 not too long ago but after installing it it didnt work (I did turn crossfire on in CCC). Any ideas? Both cards are Sapphire as well.


----------



## tastegw (Feb 19, 2013)

btarunr said:


> Sapphire won't do a Tahiti LE. They hate it. The only other brands are PowerColor (HD 7870 Myst) and VTX3D, and those cards are virtually identical to Club3D's card, since they're made on the same exact production line (TUL).



This is an XT SAPPHIRE 100354XTL Radeon HD 7870 XT w/Boost 2GB 2...
Is it not the same as the LE's?
Specs seem the same, maybe I'm missing something

At erocker

"We successfully managed to pair the Club 3D HD 7870 jokerCard with a Radeon HD 7950 and HD 7970 (reference). We casually put it through 3DMark 11 and Sleeping Dogs, and found the contraptions to scale fairly well. We noticed some micro-stutter in 3DMark 11, but Sleeping Dogs felt smooth. This could be great news for current HD 7900 series owners who can upgrade to CrossFire for a modest $249~269. We even tried our luck at unlocking disabled shaders (stream processors), which didn't work. AMD used the mod-proof fuses method to lock the shaders. Check out our Club 3D HD 7870 jokerCard review."

From the OP

What question were u answering there.


----------



## erocker (Feb 19, 2013)

tastegw said:


> What question were u answering there.



The one I quoted. I was wrong, read a couple google searches and must of read people just having problems. Also based on the fact I haven't heard of it being done. But, cool that it works.... I'd kind of like to try it out.


----------



## tastegw (Feb 19, 2013)

Ya, would be a cheaper upgrade for some folks
(Upgrade as in adding a 2nd or 3rd card)


----------



## Krantzstone (Apr 5, 2013)

*Sapphire HD 7870 XT*



tastegw said:


> This is an XT SAPPHIRE 100354XTL Radeon HD 7870 XT w/Boost 2GB 2...
> Is it not the same as the LE's?
> Specs seem the same, maybe I'm missing something
> 
> ...



Yeah, the Sapphire 7870 XT is a Tahiti LE card:
"The SAPPHIRE HD 7870 XT with Boost delivers a new priceerformance point to the series. It is based on AMD's Tahiti architecture with its 256-bit memory interface, and 1536 stream processors and 96 Texture units, unlike the remainder of the HD 7800 series that uses the Pitcairn architecture. Configured with 2GB of high speed GDDR5 memory running at 1500 MHz (6GHz effective) the SAPPPHIRE HD 7870 XT has a core clock of 925MHz which dynamically rises to 975MHz with PowerTune Boost, AMDs dynamic performance enhancement for games."

More info here: http://www.techradar.com/reviews/pc...rds/sapphire-radeon-hd-7870-xt-1130535/review

I was _this_ close to getting it, but ended up getting the PowerColor MYST instead because it was cheaper, and the Sapphire was sold out anyway.  I'm told the Sapphire has a better cooler, so that might be worth it for the extra cost of an aftermarket cooler for people planning on OC.


----------



## NeoXF (Apr 5, 2013)

ATM, R7790s and R7870XTs are best-buys, and to a lesser degree GTX660/GTX660Tis, in my country at least, not sure what's best for higher-end, but then again, there's bigger and bigger diminishing returns when going higher end.


----------

