RAM upgrade

[betelgeuse 41]

I run FS9 in XP Pro with 1GB Corsair DDR XMS3200 C2PT TwinX (2x512MB) CAS2 memory. I fly complex aircraft like the Dreamfleet Fokker 50 and the Flight One ATR, in complex sceneries, with real weather, Radio Contact, and a lot of GA AI planes. Mostly the simulation runs quite well but I get stutters now and again, and very occasionally I get a CTD near a busy airport which I think is due to memory 'overload'. RAM or graphics card?First choice is to double up the two vacant DIMM slots with the same paired RAM again. However, I cannot find a supplier. Second choice is the QVL recommendation: TwinX2048-3200CZ but I cannot find a supplier for this either. The Asus mobo is said to be 'picky' about its RAM. What to do? The mobo will support DDR400 but that's the top according to the manual and the Asus website. I don't want to drop below CAS2.ThanksJohnAsus A8N32-SLI DeluxeAMD Athlon 64 'San Diego' 2.4GhzNvidia 7800GTX 256MB Many tens of GBs in HDD partition

[Guest baksteen33]

Hi John, that's a s939 with DDR1, right? If, another 2x512MB is out of the question for optimal RAM performance and 1T (Command Rate --> Bios). 4 double sided modules have various consequences with AMD64s. 2x1GB would be best and should help seeing your description. CAS2 or 2.5 or even 3 doesn't make much of a difference with FS9 IMHO. Modules with Samsung chips have a good reputation, Apacer uses Samsung chips on their 1GB modules for example. After insertion of the new modules, set the Command Rate to 1T, perhaps overclock the CPU 10% (also a Bios option) and you'll be fine. Kind regards Jaap

[betelgeuse 41]

Thanks a bunch, Jaap.Yes, s939 DDR1. I wondered about 4 doubles and if the CAS is not to critical I can buy 2X1GB fairly cheaply. I am not an o/c man - have looked into it but always end up confused. It seems highly complicated. I am not sure about setting Command Rate either - can you explain how to do this please?John

[geoffco 0]

Hi John,I had a pair of Corsair CMX1024-3200TPC2 modules in my s939 machine (recently replaced by DDR500 for overclocking reasons). Those modules ran very happily at 2-3-3-6 1T at DDR400 speeds and I would definitely recommend them.Cheers,Geoff

[betelgeuse 41]

Hi, Geoff. Thanks. I hope you're right! I ordered up a pair of Corsair CMX1024-3200TPC2 modules just now. Cost me an arm and a leg even though they are old DDR1. My CPU is an Athlon 64 4000+ (2.4 Ghz) 'San Diego' core which is apparently very overclockable. If either you or Jaap can give me a brief idiot's guide on how to o/c without doing damage I'd be grateful. I'm using a huge Zalman cooler fan so overheating shouldn't be a problem I guess for a 10% increase. Also, I'd be glad of some info on 2-3-3-6 - what it means and how to change it - I guess in the BIOS setup somewhere. I know there's lots of stuff out there on o/c but every time I go there I get bogged down. I don't really need to understand much. Just the bare essentials. I need someone to tell me exactly what to do, and what not to do. Thanks again.John

[geoffco 0]

Hi John,The C2 PT series is still quite valuable because it works so well :) I decided not to sell mine and actually have it in my work machine right now.The following link was very very helpful to me when I first decided to teach myself some overclocking with my (then) new 939 machine - just be aware that it's really worth taking time to do it slowly and carefully: http://forums.anandtech.com/messageview.as...hreadid=1497607The link to the OC consolidation calculator from "Gogar" is broken but this is an equivalent tool (an excel spreadsheet actually): http://www.geocities.com/gtstrider/OC_Athl...lator_v1.22.xlsGood luck - but be warned, overclocking and juicing the last little bit of performance out of the machine can be addictive ;)Geoff

[Guest baksteen33]

In addition to the hardcore OC options, the Asus bios has a 'easy tweaking' section. You can select 10% OC there. The only thing you have to make sure, is the PCI-e frequency remains locked at 100Hz. The Command Rate setting is in the DRAM settings. Maybe Geoff can walk you through since you're 'brothers in arms'? Have fun! :-) Kind regards Jaap

[geoffco 0]

Hmmm, command rates eh? Well, as far as I know with an AMD S939 CPU, the general rule of thumb is "1T for 2 installed modules, 2T for 4 installed modules"... I also know that on my machine, I get 15~20% better memory bandwidth using 1T so that finished the argument for me :) I've read in a few places that in some cases, the 2T rate will give better overclocking results but I've not experienced this personally.If you'd like some further reading, go here: http://www.mushkin.com/doc/support/papers/latency.aspCheers,Geoff

[betelgeuse 41]

>The link to the OC consolidation calculator from "Gogar" is>broken but this is an equivalent tool (an excel spreadsheet>actually):>http://www.geocities.com/gtstrider/OC_Athl...lator_v1.22.xls>Hm...I'm sure you're right, Geoff, but to me this spreadsheet is incomprehensible. Mainly because I haven't a clue what all the descriptors are. Also, although I am not completely mathematically illiterate, I cannot follow this argument:if, div = CPU frequency/memory frequency then for 2550 mhz and 133 Mhz:div = 2550/133 = 19.1but in fact, according to the spreadsheet div = 6 or div = 7 :-hmmm :-hmmmThis is what I meant when I said I needed an idiot's guide. :-zhelp

[geoffco 0]

Ok, the best thing to do is to open your BIOS screen and have a look a the options available because it varies from one BIOS to another... The actual things you change are the same but they can be called slightly different things. The anandtech forum link is good as a guide of how to find the key maximum values and then the excel sheet allows you to optimise the overclock...To try an explain a little about what you cahnge:CPU = FSB x CPU Multi - That's the easiest bitHTT = FSB x HTT multi (can be 1, 2, 3, 4 or 5 but is sometimes written as 200, 400, 600, 800 and 1000) - This bit is also easy, just keep it below 1020MHz and forget about itMemory = FSB x "ratio" - This bit is more complicated (at least to me). This ratio can be 1/1, 5/6, 2/3 or 1/2 but this is often written as 200,166,133,100 because the stock FSB for the 939 is usually 200MHzThe div in that excel sheet is not something you can set but is a consequence of the others... Memory = CPU / divSo, in the example you quote of CPU = 2550 with a RAM divider of 133MHz (ie the 2/3 ratio): you could get there with FSB = 232MHz and a multi of 11. In that case, you'd set the HTT multi to 4 to get a HTT of 928MHz. For the RAM, when you select the 133 divider, your RAM will run at 232 x (133 / 200) = 154.66 MHzAnother example, my machine is running FSB 250MHz, Multi of 12, a 1:1 (200MHz!) RAM divider and HTT Multi of 4 which gives 3000MHz CPU, 1000MHz HTT and 250MHz RAM (DDR500).Hope this is helpful. When I started doing this, I made a backup of my whole primary drive, disconnected the others and just played with settings (with a lot of internet reading on my laptop) until I had an idea of what things did...GeoffPS. If you start doing this, be prepared to re-set your BIOS a few times! Find out how you do this before you need to :)