Bursting the Athlon 64 Memory bandwidth bubble - Page 6

29th May 2005, 09:38

Quote:

Originally posted by lazyman
Its called "robbing Peter to pay Paul"; yes Paul is the bastard, but Peter remains wealthy after being robbed in this case.

lol, nicely put lazyman

29th May 2005, 15:35

I'm going to test this out today and see what happens. If I can get back to 270 or more on 1 stick, I'll be ordering a 1 GB stick and running single channel. Hopefully, other people will run some benchies too. I plan on checking how vid encoding changes by testing with TMPEG and V-Dub to see if there is a difference between mpeg and divx. If anyone can do the usual Sandra stuff, we'll be able to get a good comparison.

29th May 2005, 15:36

i wouldn't hope for it, i don't think you'll be able to make up for the lost bandwith with some extra mhz on your cpu,

jmke · 29th May 2005, 15:39

the 3400+ is a S754 setup in these tests: http://www.madshrimps.be/?action=get...&articID=23 0

clock speed is all the same; to it comes down to pure core improvements, cache size and DC memory.

geoffrey · 29th May 2005, 16:41

Hey guys,
I was wondering how big the difference would be in an enthousiasts benching program like super-pi.
low fsb bad timings
low fsb tight timings
high fsb bad timings
high fsb tight timings

since I don't have A64 I can't do it myself.

jmke · 29th May 2005, 16:51

www.xtremesystems.org holds all the answer to that one

29th May 2005, 16:55

Update:
I pulled out one of my sticks of ram and tested out the rig. I also tested with the two sticks in to serve as a baseline. I used two programs to encode an avi file into 2 different formats, mpeg and divx so as to see what differences there are. Here are the results:

9 X 255 in Dual Channel Mode:
Tmpeg: 46 seconds to encode a 1 minute file.
VDub: 38 seconds to convert to divx.

9 X 255 in Single Channel Mode:
Tmpeg: 49 seconds.
VDub: 40 seconds.

9 X 270 in Single Channel Mode:
Tmpeg: 46 seconds.
VDub: 38 seconds.

Observations thus far:
1-Dual channel saves between 2-3 seconds per minute on encoding apps. This can save you between 4-6 minutes when encoding a 2 hour movie.

2-Running the rig about 135mhz faster balances things back to DC level but I think there should be an increase in performance in other areas that would justify having the higher HTT in single channel mode. Hopefully, somebody how has Sandra and other standard benchies installed will be able to test this out.

One possible fly in the ointment: The two 512MB sticks are from different manufacturers so I'm going to test the second stick to see if it is what limits me to 255 in DC mode. When I first set up the rig, I had 2 sticks from PQI and was able to run at 270 smoothly. I didn't think it would be a problem since the ram wasn't going to be run at full speed but I will test this next and report my results.

29th May 2005, 17:12

More info:
I test the other stick alone in the rig and got the exact same results. Considering its quality samsung ram, I'm not surprised. This is making me think that the SKT 939 mobos benefit more from running one stick than two. Hopefully, somebody will run the tests for Sandra, etc. and post the results. The next step for me will be seeing how high I can take the HTT with the default multiplier of 9. Hoping for 2.5 Ghz

29th May 2005, 17:44

Even more info:
Well, I decided to test moving the two sticks to channels 3 & 4 since I recalled some folks doing that and it seems to have worked for me. Am now at 9 X 270 in DC mode

I ran the two encoding tests and saw a small gain. Saved one second on TMPEG and two seconds on VDub. Not much but I'll take any little bit I can get. Also found out that 270 is about the max HTT I can reach thats totally stable with the 9 multiplier. Hope this info helps folks out a bit.

29th May 2005, 20:24

Well, 270 started giving me problems even with one stick so I'm back to my theory that the quality of the ram makes a difference. The two sticks of PQI Turbo didn't give me any problems at 270 and I was using the 166 divider which made the memory run at 224. Even with the 133 divider, the cheap value ram seems to have issues so I think people thinking about the cheapy value ram might want to consider this.

29th May 2005, 15:39	#54
jmke Madshrimp Join Date: May 2002 Location: 7090/Belgium Posts: 79,021	the 3400+ is a S754 setup in these tests: http://www.madshrimps.be/?action=get...&articID=23 0 clock speed is all the same; to it comes down to pure core improvements, cache size and DC memory. __________________

29th May 2005, 16:41	#55
geoffrey [M] Reviewer Join Date: Nov 2004 Posts: 4,127	Hey guys, I was wondering how big the difference would be in an enthousiasts benching program like super-pi. low fsb bad timings low fsb tight timings high fsb bad timings high fsb tight timings since I don't have A64 I can't do it myself. __________________

29th May 2005, 16:51	#56
jmke Madshrimp Join Date: May 2002 Location: 7090/Belgium Posts: 79,021	www.xtremesystems.org holds all the answer to that one __________________

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29th May 2005, 15:35	#52
perdomot Posts: n/a	I'm going to test this out today and see what happens. If I can get back to 270 or more on 1 stick, I'll be ordering a 1 GB stick and running single channel. Hopefully, other people will run some benchies too. I plan on checking how vid encoding changes by testing with TMPEG and V-Dub to see if there is a difference between mpeg and divx. If anyone can do the usual Sandra stuff, we'll be able to get a good comparison.

29th May 2005, 15:36	#53
GIBSON Posts: n/a	i wouldn't hope for it, i don't think you'll be able to make up for the lost bandwith with some extra mhz on your cpu,

29th May 2005, 16:55	#57
perdomot Posts: n/a	Update: I pulled out one of my sticks of ram and tested out the rig. I also tested with the two sticks in to serve as a baseline. I used two programs to encode an avi file into 2 different formats, mpeg and divx so as to see what differences there are. Here are the results: 9 X 255 in Dual Channel Mode: Tmpeg: 46 seconds to encode a 1 minute file. VDub: 38 seconds to convert to divx. 9 X 255 in Single Channel Mode: Tmpeg: 49 seconds. VDub: 40 seconds. 9 X 270 in Single Channel Mode: Tmpeg: 46 seconds. VDub: 38 seconds. Observations thus far: 1-Dual channel saves between 2-3 seconds per minute on encoding apps. This can save you between 4-6 minutes when encoding a 2 hour movie. 2-Running the rig about 135mhz faster balances things back to DC level but I think there should be an increase in performance in other areas that would justify having the higher HTT in single channel mode. Hopefully, somebody how has Sandra and other standard benchies installed will be able to test this out. One possible fly in the ointment: The two 512MB sticks are from different manufacturers so I'm going to test the second stick to see if it is what limits me to 255 in DC mode. When I first set up the rig, I had 2 sticks from PQI and was able to run at 270 smoothly. I didn't think it would be a problem since the ram wasn't going to be run at full speed but I will test this next and report my results.

29th May 2005, 17:12	#58
perdomot Posts: n/a	More info: I test the other stick alone in the rig and got the exact same results. Considering its quality samsung ram, I'm not surprised. This is making me think that the SKT 939 mobos benefit more from running one stick than two. Hopefully, somebody will run the tests for Sandra, etc. and post the results. The next step for me will be seeing how high I can take the HTT with the default multiplier of 9. Hoping for 2.5 Ghz

29th May 2005, 17:44	#59
perdomot Posts: n/a	Even more info: Well, I decided to test moving the two sticks to channels 3 & 4 since I recalled some folks doing that and it seems to have worked for me. Am now at 9 X 270 in DC mode I ran the two encoding tests and saw a small gain. Saved one second on TMPEG and two seconds on VDub. Not much but I'll take any little bit I can get. Also found out that 270 is about the max HTT I can reach thats totally stable with the 9 multiplier. Hope this info helps folks out a bit.

29th May 2005, 20:24	#60
perdomot Posts: n/a	Well, 270 started giving me problems even with one stick so I'm back to my theory that the quality of the ram makes a difference. The two sticks of PQI Turbo didn't give me any problems at 270 and I was using the 166 divider which made the memory run at 224. Even with the 133 divider, the cheap value ram seems to have issues so I think people thinking about the cheapy value ram might want to consider this.