M17x DPC Latency

[Alek123]

Thanks , that cleared up things for me. I sent you a PM with the link to the log. It's taken during Just Cause 2.

[unclewebb]

Just so others know, Alek123 has some serious clock modulation issues. This was dropping down to as low as 12.5% during his log file which kills gaming performance or any performance for that matter. When a CPU is being this badly throttled, it can also lead to an 8 fold increase in DPC latency spikes. Something to keep in mind when you start seeing huge red spikes. I hope you're able to get Dell to come clean about this issue Alek123 and provide you with some sort of solution, preferably an M17x R2. This is definitely not an isolated incident.

[BatBoy]

Alek, what display driver are you using? Be aware, JC2 can have serious issues (stuttering/fps drops especially during the benchmark) with various NV display drivers. I cant recall the exact driver ver, but I recall testing one driver and found that JC2 crapped out badly with FPS. Didn't bother to check CPU throttling at the time.

Give me the driver ver you are running and I will try to replicate the throttling you are seeing with JC2.

[scook9]

So it is the exact same things me and Elkay were discussing in the stutter thread. Shame dell thought such a bad "feature" was necessary

[unclewebb]

His log file showed the same old stuff that we've seen before. Here's part of it.

  DATE     TIME    MULTI   C0%   CKMOD  CHIPM  DTS
09/24/10 22:56:43   7.50   73.8  100.0  100.0   30
09/24/10 22:56:55   7.50   68.1  100.0  100.0   29
09/24/10 22:56:56   7.34   41.0  100.0  100.0   29
09/24/10 22:56:57   7.50   89.3  100.0  100.0   28
09/24/10 22:56:58   7.50   91.0  100.0  100.0   28
09/24/10 22:56:59   7.50   89.9  100.0  100.0   28
09/24/10 22:57:00   7.50   89.4  100.0  100.0   28
09/24/10 22:57:01   7.50   93.1  100.0  100.0   28
09/24/10 22:57:02   7.50   93.5  100.0  100.0   27
09/24/10 22:57:04   7.50   90.7  100.0  100.0   28
09/24/10 22:57:05   7.50   86.7  100.0  100.0   27
09/24/10 22:57:06   7.50   87.6  100.0  100.0   27
09/24/10 22:57:07   7.50   87.5  100.0  100.0   27
09/24/10 22:57:08   7.50   88.4  100.0  100.0   27
09/24/10 22:57:09   7.50   84.7   12.5  100.0   27
09/24/10 22:57:11   7.50   44.1   12.5  100.0   31
09/24/10 22:57:12   7.49   33.1   25.0  100.0   31
09/24/10 22:57:13   7.49   38.8   25.0  100.0   30
09/24/10 22:57:14   7.49   41.7   25.0  100.0   30
09/24/10 22:57:15   7.49   41.7   37.5  100.0   30
09/24/10 22:57:16   7.49   46.1   37.5  100.0   29
09/24/10 22:57:17   7.49   46.7   37.5  100.0   30
09/24/10 22:57:18   7.49   47.4   50.0  100.0   29
09/24/10 22:57:19   7.50   54.3   50.0  100.0   29
09/24/10 22:57:20   7.50   54.9   50.0  100.0   29
09/24/10 22:57:21   7.50   55.5   62.5  100.0   29
09/24/10 22:57:22   7.50   62.7   62.5  100.0   28
09/24/10 22:57:23   7.50   63.7   62.5  100.0   28
09/24/10 22:57:24   7.50   63.0   75.0  100.0   28
09/24/10 22:57:25   7.50   71.6   75.0  100.0   28
09/24/10 22:57:26   7.50   73.1   75.0  100.0   27
09/24/10 22:57:27   7.50   72.0   75.0  100.0   27
09/24/10 22:57:28   7.50   76.9   75.0  100.0   26
09/24/10 22:57:29   7.50   77.8   75.0  100.0   26
09/24/10 22:57:30   7.50   77.2   75.0  100.0   26

Clock modulation going from 100.0% down to 12.5% is a good way to instantly send frame rates into the toilet. This also causes DPC Latency to spike when this happens. It stabilized at 75.0% for a while and then went through a few cycles where it would drop back down, again and again.

Makes you wonder what the hell was Dell thinking when they came up with this scheme. Clock modulation murders performance and makes a computer unusable. I hope he can get this sorted out but without an upgrade to an R2, that's not too likely.

[scook9]

You also have to wonder what the hell they were thinking since this is not a new problem for them. It was in the M17 as well as various other past models (maybe it is actually a Flextronics problem as they would be the ones that actually make the BIOS)

[Alek123]

Unfortunately , i don't think i can get a replacement. The laptop was bought from the US , and i'm living in Romania, and there are almost no chances i can get an R2 replacement here.

BatBoy , i'm running 197.84 Dell drivers , as pretty much all from Nvidia website are giving me BSODs/Black screens/Restarts.

[unclewebb]

Here's an example of how ThrottleStop should be set up to reduce the amount of clock modulation throttling you are seeing.



A Q9000 supports Intel Dynamic Acceleration which means when the CPU is lightly loaded, it can occasionally use the 8.5 multiplier. The CPU supports this but your motherboard might have this feature disabled. If the Disable Turbo button in ThrottleStop is always checked and you can't uncheck it then this feature has likely been disabled by the bios.

If you can uncheck the Disable Turbo box and it remains unchecked then by all means do that and increase the Set Multiplier box to 8.5.

The biggest problem you are having is the excessive use of clock modulation. Using ThrottleStop to counter act that will not totally cure that problem but it might make a huge difference and greatly improve your frame rates while gaming.

My example above is on a CPU with a 200 MHz bus speed so your bus speed will show 266 MHz. Other than that, ThrottleStop should look more or less like the above picture. You can also start with slightly more voltage like 1.10 but see if you can get that down to 1.05 while still maintaining full stability while running a benchmark like wPrime or Prime95.

[scook9]

You may want to look at undervolting your gpus as well. Lowering the power draw will definitely help your situation. If that does not work you can also try to get some 4870s from dell.

Also, UncleWebb, does that mean you can still unlock and alter the voltage on non extreme cpus with ThrottleStop?

[unclewebb]

The ThrottleStop Voltage ID feature works great on the Core 2 Duo and Core 2 Quad CPUs. You can set that to whatever core voltage you like. Unfortunately, Intel changed how this works on the newer Core i CPUs so this feature is not available for them.

Even if you are using an Extreme QX9300 and you've used ThrottleStop to unlock and increase your multiplier, you still have full control over the voltage ID it uses. For the non-Extreme CPUs like the Q9000, you can lower the VID voltage but you won't be able to raise it or the multipliers beyond the default values.

I've seen other users running their Q9000 reliably at 1.05 volts so that's why I suggested that number. Since this throttling problem is 100% power related, anything you can do to lower power consumption is going to help. Under volting both the CPU and GPUs will definitely make a difference and should reduce or eliminate clock modulation throttling.