Low graphics card memory speed

[humilitys_hand]

Hey guys...

 

About 2 months ago I bought 2 XFX HD 7770 Core Editions ( FX-777A-CGFV ).

 

I reformatted computer A and for kicks I ran Heaven Benchmark and discovered it was stuttering really bad. I then noticed the memory was only running at 667mhz. So I hopped over to computer B and it is doing the same thing... running at 667mhz. I went back to computer A and tried to bump up the memory speed to around 1000mhz through CCC 14.4 and it crashed everything. I think the stock speed should be around 1000 to 1200 mhz.

 

CCC is frustrating me at the moment cause AMD took away the "test custom clocks" button so when I try to apply a bad clock setting it gets caught in a crash loop cause it is saving the bad clock settings.

 

The cards are only 2 months old and I never had them overclocked before. Power supply, motherboard and cooling should be way over the top in computer A (So that is the one I would like to focus on for the moment).

 

To be clear... the cards are not throttling... they stay @ 667mhz. I'm going to head over and download Afterburner and see if I have better luck. Any advice on what would be causing this would be appreciated. 

 

Computer A

AMD FX 8320 (Overclocked to 4.72Ghz with H100i cooler

Asus Sabertooth R2.0

8gb Ballistix Sport

1100W OCZ PSU

XFX HD 7770 Core Edition FX-777A-CGFV

Windows 8 64bit

Frictal Design Define R4 XL

 

Computer B

AMD FX 4130 (Overclocked 4Ghz) with 212 evo cooler

MSI 970A-G46

4gb Corsair xms3

500w Diablotek PSU

XFX HD 7770 Core Edition FX-777A-CGFV

Windows 8 64bit

I forget the case... generic

 

Stay safe and have fun... Much love... Mitch

[AlwaysFSX]

Memory speeds either show as 1/4, 1/2, or 1/1 of what they actually are. It sounds about right though from what I remember with my old 7770.

[humilitys_hand]

Memory speeds either show as 1/4, 1/2, or 1/1 of what they actually are. It sounds about right though from what I remember with my old 7770.

Well I tried Afterburner and got the memory clock to 1000mhz and it seems stable. It crashes anything much above that. I'd rather not run Afterburner on a permanent basis though. Still baffles me why it is defaulting to 667mhz in CCC and why it's not stable when I bump it up to 1000mhz in CCC.

[AlwaysFSX]

Well I tried Afterburner and got the memory clock to 1000mhz and it seems stable. It crashes anything much above that. I'd rather not run Afterburner on a permanent basis though. Still baffles me why it is defaulting to 667mhz in CCC and why it's not stable when I bump it up to 1000mhz in CCC.

Same reason my memory clock shows at 800 MHz when it's running at 1600MHz... DDR = Double Data Date.

[D2ultima]

Run GPU-Z and tell us what your GPU-Z clock is at. I don't know how CCC reads memory clocks. GDDR5 has 3 ways to read memory so it's tricky. You could have actual clock, doubled clock and effective clock. I suggest checking GPU-Z screenshots of other 7770 cards and seeing what it's supposed to look like and comparing the two.

[humilitys_hand]

OK I took some screen shots with GPUZ. The first is before overclock and the second is after. I also have 2 other computers with Sapphire hd 7770. They are showing 1125mhz on everything with stock settings. I'm guessing at this point that CCC 14.4 is loading the wrong speeds for this card and has the correct speeds for the Sapphire cards.

[D2ultima]

Bro that is not in any form of readable size. You should put the pics on imgur or some other hosting site so we can at least upsize them.

 

Anyway, as for if your card won't apply the proper clocks, then something could be wrong indeed. Have you tried flashing the vBIOS? It may fix the problem. You said swapping the card to different PCs didn't work, but other machines with the same kind of card work fine? If that's the case, then there's your fix.

 

Alternately, you could just RMA the card.

[humilitys_hand]

Ok… an update on what I found. The new CCC drivers are seeing some (my Sapphire cards with) HD 7770s as R7 200. My XFX cards with 2 GB ram are still showing as HD 7770s but the ram it defaulting to 667mhz. I am able to force the ram to normal speed in afterburner to around 1000mhz but it is def not as stable as it use to be.

 

I’m chalking it up to driver issues at this point but it does raise a question. Since the r7 200s are basically rebranded hd 7770 I am wondering if it is possible to crossfire two hd 7770s without a crossfire bridge since the R7 200 series does not require a crossfire bridge.  I’ll try playing with it more later this week.

[dragoon20005]

Ok… an update on what I found. The new CCC drivers are seeing some (my Sapphire cards with) HD 7770s as R7 200. My XFX cards with 2 GB ram are still showing as HD 7770s but the ram it defaulting to 667mhz. I am able to force the ram to normal speed in afterburner to around 1000mhz but it is def not as stable as it use to be.

 

I’m chalking it up to driver issues at this point but it does raise a question. Since the r7 200s are basically rebranded hd 7770 I am wondering if it is possible to crossfire two hd 7770s without a crossfire bridge since the R7 200 series does not require a crossfire bridge.  I’ll try playing with it more later this week.

you will need to use the bridge for crossfire to work

 

only the 290 and 290x do not need the bridge

[D2ultima]

Wish I could tell you. I only know about SLI in any kind of depth.

[dragoon20005]

if i am correct the way to calculate the GDDR5 speeds is 4.5GHz divide by 4 = 1125MHz 

 

if not the DDR speeds is 2250MHz

 

this is for your GPU

[D2ultima]

if i am correct the way to calculate the GDDR5 speeds is 4.5GHz divide by 4 = 1125MHz 

 

if not the DDR speeds is 2250MHz

 

this is for your GPU

This is correct. GDDR5's base clock is /4 of the effective. Some overclocking programs, however, will read the doubled memory clock, such as nVidia inspector. I believe MSI Afterburner does this too.

[humilitys_hand]

you will need to use the bridge for crossfire to work

 

only the 290 and 290x do not need the bridge

 

Ok the R7 250X and the HD 7770 are both based on the Cape Verde XT graphics processer. The R7 250X is a rebranded HD 7770. The R7 250X can crossfire 2 GPUs without a crossfire bridge per this article on AMDs site.

 

http://www.amd.com/en-us/markets/game/technologies/r7

 

(Click on “Specifications”)

[dragoon20005]

Ok the R7 250X and the HD 7770 are both based on the Cape Verde XT graphics processer. The R7 250X is a rebranded HD 7770. The R7 250X can crossfire 2 GPUs without a crossfire bridge per this article on AMDs site.

 

http://www.amd.com/en-us/markets/game/technologies/r7

 

(Click on “Specifications”)

but do your GPU has the gold fingers like the Geforce for their SLi?

[,,,,,,,,,,,,,,,,,,,,,,,,,,]

Maybe its throttling?

Make sure the the fans are working?

Check the temps? Im not too sure, I dont remember my 7770 clocks but they were higher than that.