Twin2X2048-6400C4 max speed?

[Ken429]

I have three systems each with 2G of Twin2X2048-C4 memory installed. One has a E6750, the second has a E6600 and the "old" system has a Prescott 3.2 processor. The Duo processors are running on P35 chip MB's and the Prescott is running on a P965 chip MB. The two P35 systems are set at 2.1v and 4-4-4-12 2T timings. The FSB:DRAM are set to 1:1. The Prescott is set at the SPD defaults. I am trying to better understand what I want to do to get good stable overclocking on the three systems. The External Clock on the E6750 (8 multiplier) is overclocked at 400 and the FSB is at 1600. The system is very stable and running cool with the stock Intel cpu fan. Best I can tell the memory will support 1600 (800X2)? If that is true, what can I expect over the 1600? If I change the timings will it allow me to further increase the External Clock? Which is better/faster higher External Clock settings or lower memory timings? Does the same "rules" apply to the E6600 which has a lower FSB and a 9 multiplier? The reason I'm even asking all these questions is the E6600 system would hang if I tried make a minor change to the External Clock before setting the FSB:DRAM 1:1...and...the E6750 is really fast on cpu intensive stuff. For some reason the system default was 2:3 on the E6600. The E6750 system setup day one at 1:1. I'll leave the Prescott for another session!

[DerekT]

Your E6750 has a FSB set to 333MHz and is overclocked to be running at 400 X 4 (Quad Data Rate) = 1600Mhz. Your DRAM is running at 400 X 2 (Dual Channel Rate) = 800Mhz.

 

Your E6600 has a FSB set to 266MHz and is running at 266 X 4 (Quad Data Rate) = 1066Mhz. Your DRAM is running at 400 X 2 (Dual Channel Rate) = 800Mhz.

 

I would not mess around with the DRAM timings as you have already purchased low timing (4-4-4-12) DRAM and it's not a good idea to try and lower them further. Stability issues can certainly arise.

 

Your 800Mhz Memory can NOT support 1600Mhz. No DDR2 memory can even come close to that value. They are 400Mhz Modules, which, when running in Dual Channel Mode run at 800Mhz.

 

You can attempt to raise timings and speed on the DRAM if you wish but 1000Mhz with 5-5-5-15 and 800MHz with 4-4-4-12 are about the same in speed, hence the reason people by 6400C4 rather than 6400C5 as 6400C4 is quite a bit faster than 6400C5.

 

I have three systems each with 2G of Twin2X2048-C4 memory installed. One has a E6750, the second has a E6600 and the "old" system has a Prescott 3.2 processor. The Duo processors are running on P35 chip MB's and the Prescott is running on a P965 chip MB. The two P35 systems are set at 2.1v and 4-4-4-12 2T timings. The FSB:DRAM are set to 1:1. The Prescott is set at the SPD defaults. I am trying to better understand what I want to do to get good stable overclocking on the three systems. The External Clock on the E6750 (8 multiplier) is overclocked at 400 and the FSB is at 1600. The system is very stable and running cool with the stock Intel cpu fan. Best I can tell the memory will support 1600 (800X2)? If that is true, what can I expect over the 1600? If I change the timings will it allow me to further increase the External Clock? Which is better/faster higher External Clock settings or lower memory timings? Does the same "rules" apply to the E6600 which has a lower FSB and a 9 multiplier? The reason I'm even asking all these questions is the E6600 system would hang if I tried make a minor change to the External Clock before setting the FSB:DRAM 1:1...and...the E6750 is really fast on cpu intensive stuff. For some reason the system default was 2:3 on the E6600. The E6750 system setup day one at 1:1. I'll leave the Prescott for another session!

[Ken429]

Thanks for the quick response and clarification on what I'm trying to ask. I was ok until I made the 1600 memory leap!! So...CPU-Z says the E6750 system under the CPU Tab - Bus Speed 400, Rated FSB 1600 and under the Memory Tab it shows DRAM Frequency of 400. What you are saying is at FSB setting of 400 I'm pushing the memory at it's rated speed? Next question, short of trial and error, how much farther can I push the Corsair memory by raising the FSB without causing too much stress on the system? At a FSB setting of 400 or 8*400=3.2 the E6750 is still running at normal temperatures. When I change the FSB to 405 the DRAM Frequency goes to 405 and the system is still stable. I guess that makes sense since I have the FSB:DRAM set at 1:1. Based on all the OC'ing stuff on the web I am no where near the limit on abit IP35 Pro/E6750/FSB/DDR2 800 hardware but you can't always believe what is on the web!?

[DerekT]

You are correct. That is what I am saying.

Download OCCT Perestroika for a quick, hard and fast CPU stability test --->

Here

Download memtest from--->

Here

and extract the ISO image. Burn the ISO image to an CD-ROM disk.

Test with Memtest and then use OCCT for an hour. If stable, continue. If you set the Timings to 5-5-5-12, you should be able to move to ~1000Mhz. Set to 4-4--4-12, you can look for ~850 - 900Mhz with 2.1v. I would not go higher than 2.1v as overvolting characteristics will void your warranty.

[Ken429]

That is what I was looking for. I'll try going slowly to 425 on the E6750 system and see if it has any heat issues. 3.4 seems like a good number. We'll see where the E6600 goes. Heat will probably become an issue before memory limitations. I'm currently running the E6600 at 320 FSB and have not noticed an increase in cpu temps yet. I have been using Nero Recode to compress a full length DL movie to a single layer DVD - Tends to run the cpu's at close to 100% for 4 or 5 minutes. Not real scientific so I'll try the program you suggested. Thanks again for the help.

[DerekT]

That is what I was looking for. I'll try going slowly to 425 on the E6750 system and see if it has any heat issues. 3.4 seems like a good number.

With a stock Intel cooler, well I actually, don't like the stock Intel for its poor Drop Delta. The temperature drop delta is not taken into account when running stress testing or a CPU running synthetically at full bore. With a good cooler, you will not reach as high a thermal when running real system intensive applications.

 

So basically, the temperature Drop Delta is the length of time it takes for the temperature of the CPU to drop. For example, in gaming and application use, you do not make use of the CPU 100% of the time. There are points where data is being transferred, CPU use drops in multiple environments, multiplexing needs time to revive a stream, etc... During these times, the processor cores load drops and so does the thermal output of the cores. On a stock cooler, the time between the drops and the loads is marginalized by the coolers inability to release the thermal output and thus the CPU does not benefit nearly as much. With a cooler such as a Thermaltake BigTyphoon, Tuniq Tower and Thermalright Ultra-120 xTreme, you will not have thermal issues. Thermalright has fixed an issue with their new released edition, and this is one of the best coolers around at the moment. It has a drop delta that is rapid and the CPU will benefit greatly from such a cooler. But even the Arctic Freezer is better than stock and with a 3.0/3.2Ghz overclock, it works decently. For the money you spent on this system, I don't think it is a good idea to cheap out by $20.00 or so. Be good to your CPU. Look at the Arctic Cooler Freezer 7 (5 year Warranty).

 

We'll see where the E6600 goes. Heat will probably become an issue before memory limitations. I'm currently running the E6600 at 320 FSB and have not noticed an increase in cpu temps yet. I have been using Nero Recode to compress a full length DL movie to a single layer DVD - Tends to run the cpu's at close to 100% for 4 or 5 minutes. Not real scientific so I'll try the program you suggested. Thanks again for the help.

 

You're welcome. I would look to some aftermarket cooling for the E6600 as well. AC Freezer 7 is a good cheap cooler that does a more than adequate job.

 

This is a good program to test the CPU cores and find out what VID you are running.

 

http://www.alcpu.com/CoreTemp/

[Ken429]

I already have a Zalman CNPS7000 CU, a Zalman CNPS9500 LED, and a Zalman 9700 LED. I bought these back in the Prescott days. I have the CNPS 9500 AT on my wish list at Egghead. Zalman finally has a 4-wire version that does not need all their manual control hardware. However, the abit IP35 Pro MB has Q-Fan settings that actually work with 3-wire cooling fans! I know the Zalman costs a little more and is a pain to install but I like the "bolt" down holder since the MB's are in Lian Li PC-61 mid-tower cases. Actually I thought I was happy with the stock settings and Intel coolers and would not get into OC'ing but it's hard to resist. Any opinions?

[DerekT]

I'm not big on the Zalmans in terms of performance. I go with a Sunbeam Tuniq Tower for Dual Cores, and a Thermalright Ultra Xtreme 120 with dual 120's for my Quad Core Server.

 

But my overclocks are higher as well. 3.6Ghz on the Q6600 Quad Core and 4.2Ghz on the Dual Core Xeon 3110.

 

 

 

I already have a Zalman CNPS7000 CU, a Zalman CNPS9500 LED, and a Zalman 9700 LED. I bought these back in the Prescott days. I have the CNPS 9500 AT on my wish list at Egghead. Zalman finally has a 4-wire version that does not need all their manual control hardware. However, the abit IP35 Pro MB has Q-Fan settings that actually work with 3-wire cooling fans! I know the Zalman costs a little more and is a pain to install but I like the "bolt" down holder since the MB's are in Lian Li PC-61 mid-tower cases. Actually I thought I was happy with the stock settings and Intel coolers and would not get into OC'ing but it's hard to resist. Any opinions?

[Ken429]

Well, I guess I'm a diehard Zalman fan. I went and bought the Zalman 9700 NT and installed it on the abit/E6600 system. I know there are better/cheaper coolers but this one looks nice and I don't plan on pushing the system to the limit! I was really surprised to see the max cpu temps drop from 59c to 41c when running under full load overclocked to 2.8. Now, on to the abit/E6750 system.

[DerekT]

Well, I guess I'm a diehard Zalman fan. I went and bought the Zalman 9700 NT and installed it on the abit/E6600 system. I know there are better/cheaper coolers but this one looks nice and I don't plan on pushing the system to the limit! I was really surprised to see the max cpu temps drop from 59c to 41c when running under full load overclocked to 2.8. Now, on to the abit/E6750 system.

 

They are not the best in cooling, but they are certainly not a bad cooler and they are one of the best in looks. With a 2.8GHz overclock you do not need the highest end cooling anyway so I agree with you. You will find a higher overclock with the E6750 I would think. I had no issues with 3.4 - 3.6Ghz on those chips.