GPU Specified Clock Speeds vs. GPU-Z Reading

[amantes]

Hi there! I recently bought a GTX 750 from Gigabyte. It's working fine and runs games like a charm, but some things confuse me. This is the first graphics card I've bought myself so I don't exactly understand how clock speeds work. Here's the thing. I got GPU-Z to learn more about my card and see how much memory it's using, etc. By specification on Gigabyte's page it should have:
Core Clock: Base 1059MHz / Boost 1137MHz
Memory Clock: 5000MHz
But when I fire up GPU-Z while running Dying Light, I get this:

For starters, the memory clock is set considerably lower. Then, at the sensor, even the core is running lower than base. Can someone explain to me what this means? Thank you!

 

[JimF_35]

Remember with DDR memory you have to double it it because that is what Double Data Rate (DDR) stands for. Also you should be looking at all tests under load because the system underclocks stuff at idle to save power. Run Furmark when looking at your values.

http://www.ozone3d.net/benchmarks/fur/

 

[Epsilon_0EVP]

Look at the GPU load. It's only at about 3/4. That means the GPU isn't being fully used, which makes sense since Dying light can be CPU-bottlenecked at times. To save power, modern GPU's downclock automatically when that happens. It's nothing to really worry about. As JImF_35 said, run a stressing benchmark and you should see the GPU clock go right up.

 

[amantes]

Ah yes, the doubling. Thanks, Jim. I'll run that test and see how it goes. I'm still confused about the numbers though. I mean, for the core it says base and boost as expected, but for the memory it has this weird number that's still less than specified even when doubled. And I know it's supposed to underclock when idle, but I thought 75% load was far from that. I guess the scaling is not linear? Sorry, I'm still a noob at graphics card.

Thanks, Epsilon! I'm just confused why it goes under the base value. I thought that was the minimum for the core to operate at, and it would clock up to the boost speed when needed. Maybe I thought wrong. And yes, my CPU is bottlenecking, I'm using a bare Celeron that's always at the ~100% mark while running the game.

 

[Epsilon_0EVP]

As I mentioned, graphics cards will downclock when they don't need to go at full power. This is a power-saving measure, since a lower clock will use less power. The base clock is not exactly the lowest clock the card can run at, though; it's the lowest clock the card can run at at full load under it's thermal limits. If it happens to have some overhead in thermals, then it can boost up to its boost clock. But if it doesn't need to run at full power, it'll go down as low as it can go to save power.

With a Celeron, it's not surprising your card is not running at full power. It's quite limited in performance by that single core CPU 😛 I don't think anything is particularly wrong with your system; we might just need an upgrade soon on the CPU side, though.

 

[amantes]

I see, thanks for the explanation!
Hey now, it's a dual core, it's not THAT old of a Celeron 😀 It's a G1840. Second cheapest option for Haswell on the market. I plan to pick up an i5 on a newer socket eventually. I'm still surprised how well the game runs, as I am way below the minimum requirements for CPU. My friend says I'm gonna kill it running at 100% all the time.

 

[Epsilon_0EVP]

Interesting, I could've sworn all Celerons were single core now 😛 Today I learned

It is rather surprising that it still works for gaming. I would upgrade soon, though; games are already coming out that flat-out do not run on dual core CPU's.

 

[JimF_35]

Just wondering why are you so concerned about your memory clock?

The memory is a bottle neck on your graphics not a performance enhancer. More and faster memory means less bottleneck for the GPU. There is a point were raising its speed will no longer out pace the other bottle necks. Also like stated above, your video memory is not your problem it is your CPU.

 

[amantes]

@Epsilon Yeah I know I need an upgrade, but I can't afford it right now. I bought the cheapest possible modern config because I was desperate for a new rig, I spent like 8 years on a Pentium 4 with a GF6600. I could not even run TF2. So for the time being I'm happy with what I have. I'll probably shoot for an i5 when Skylake comes about.

@Jim I'm not concerned, I'm just confused. Like I said, I'm new at working with graphics cards so I'm trying to figure out how things work. Yeah I know my CPU is limiting, but the gpu is only clocking the memory at 50% while at 75% load. But I doubt it's a linear progression. Also, on the "Graphics Card" tab, the core clocks are stated as specified, only the memory clock looks weird.

Btw, am I really gonna kill my CPU? According to SpeedFan it's only at 38 degrees while playing.

 

[JimF_35]

Here is some numbers for you to show you what you are doing is pointless.

Test 1
I set my card to +82 memory overclock. My base is 1502 and that gives me 1584 * 2 = 3168 MHz This is my sweet spot by the way. Then I run Unigen.

- 3168 MHz (Set)
- 3086 MHz (Reported by GPUz)
- 56.9 FPS

Test 2
I set my card to +1914 memory overclock. My base is 1502 and that gives me 2500 * 2 = 5000 MHz like yours. Then I run Unigen.

- Never Mind it crashed. I can't clock that high.

Test 3
I set my card to +163 memory overclock. My base is 1502 and that gives me 1665 * 2 = 3330 MHz. Then I run Unigen.

- 3330 MHz (Set)
- 3168 MHz (Reported by GPUz)
- 57.7 FPS

As you can see not a major increase in performance.

 

[amantes]

Thanks for the numbers! But I'm not sure what you mean, I'm not really doing anything. I mean, I'm not adjusting any clocks, I'm leaving everything at stock and I'm wondering why GPU-Z reports that number. But yeah I guess your second test where set and reported don't match answers that. So where should I see the set, and why is there a mismatch?

 

[JimF_35]

Oh, sorry I thought you were over clocking and wondering why it did not show. I think I got the answer for you. When I said multiply it by 2 I was wrong. I guess video memory uses a quad pump which means you have to multiply by 4...

http://www.enthusiastpc.net/articles/00001/3.aspx

This should make your numbers match now. Sorry for the confusion.

 

[amantes]

I'm far from overclocking, but I intend to do it eventually. That's why I'm trying to make sense of the readings on GPU-Z as a start 😀
Ahh, now everything fits. See, we all learn something in the end 😀 That's why I love this forum. Thanks for the research!

 

[rm_killer]

Remember with DDR memory you have to double it it because that is what Double Data Rate (DDR) stands for. Also you should be looking at all tests under load because the system underclocks stuff at idle to save power. Run Furmark when looking at your values.

http://www.ozone3d.net/benchmarks/fur/

hi
i have a question:
when i use GPU Z to see my GPU MEmory clock i see this :

but when i use sensor in stressing my gpu gpuz show me this :

seeing?
my Gpu memory clock dos not over to 900 mhz and stay on 243 mhz
what's happened ?
why ?
plz help me
icant speek eng currectly
sorry

 

[JimF_35]

Remember with DDR memory you have to double it it because that is what Double Data Rate (DDR) stands for. Also you should be looking at all tests under load because the system underclocks stuff at idle to save power. Run Furmark when looking at your values.

http://www.ozone3d.net/benchmarks/fur/

seeing?
my Gpu memory clock dos not over to 900 mhz and stay on 243 mhz
what's happened ?
why ?
plz help me
icant speek eng currectly
sorry

You should post a new thread on the forum to get this better answered. Also, do not forget to put the specs of your RAM and Motherboard in the post. Need the make and model of each.