OT - memory and latency

[Guest SD Sim]

I'm sorry for the OT post, but it's been a very long weekend, and I'm looking for some help. I decided to assemble a new system to use with WidevieW (my final one to give me a right side view). I spent a few weeks doing my homework (as much as I could), and decided in the end to go with a Gigabyte MB (Tom's hardware top pick for KT333 chipsets) with Corsair 3000 memory. The details aren't important, because after roughly 24 hours of heartache in 2 days, I'm certain that the MB is defective (to review how I arrived at this conclusion would probably be more painful to methan to you).After numerous benchmark tests (Gigabyte board couldn't complete any 3D Mark2001SE tests), I found that there was no difference between my Corsair 3000 (CL2 platinum) and Samsung (CL2.5) memory modules when running my current "server". One of the reasons I bought the Corsair was that I thought the CL2 would improve performance. So here is my question/problem: I now have to admit to myself that I still don't really understand cas level. My rudimentary understanding (from Tom's hardware) is that this has to do with the latency period after a processor cache miss (failure to load the necessary instruction set). The lower the cas level, the shorter the number of clock cycles before the needed instruction set is delivered from memory. After seeing Paul's score with his new system, I hoped that the step up to better memory would imrpove my performance. What I don't know is how to set up my BIOS to take advantage of the improved memory. I thought that the BIOS normally detects the memory module and sets the optimal cas levels. However, when I placed the Corsair memory in the "server", it still showed CL2.5. I know that I'm still somewhat short on information here, but I think I've gone on long enough. Elrond, Paul, Max, others - care to take some time to help out this poor misdirected neophite? :-shy

[Guest]

Hi David,While I'm going to take your advice from another thread and get some sleep (can barely keep my eyes open! :-doh), I'll take a quick stab at this first - if not in detail so forgive me (I can hear the sighs of relief though :-))...While you didn't specify the exact motherboard you are referring to, I'll assume it has an Award BIOS (I assume its the 7VRXP since its a great board and I know you :-)). If so, you should see the "Chipset Feature Setup" as option three in the root menu. Open it and you'll see the memory tweaks.I can't specifically tell you exactly what to set here as it'll all depend on your system, but here are some pointers:--Configure SDRAM by SPD: Disabled (otherwise your dram timings will be set by the settings as encoded on the dram boards themselves - it will ignore any of your own settings)Top Performance: EnabledFast Command: UltraDRAM Freq: 333SDRAM CAS # Latency: 2SDRAM Command Rate: 1T(NOTE: these are the most demanding settings: you may have to back off of them to retain stability, depending on a lot of your other components - PCI cards, video card, AGP settings, etc)--Its in the Hardware Monitor setup page that you can boost or lower the voltages to your memory modules, raise and lower the FSB speed, etc. If you are wanting to seriously overclock, this is your area. Do note that some memory modules (even of same-brand and make) may need some voltage tweaks to get the best stability while their brothers may not. This whole section is beyond what you're trying to do though, so don't think I'm recommending tweaking anything here... I know you're extremely thoughtful in hardware matters however, so you can read up on a lot of this if you desire in the future.For a better guide than my ramblings here, I highly suggest Adrian's BIOS Optimization Guide. While all disclaimers should be made for my remarks and what is included in that guide (for others reading this), its a good resource for the various general BIOS settings available:http://www.rojakpot.com/Speed_Demonz/BIOS_...Guide_Index.htmSorry couldn't be more detailed tonight, but if Paul, Max or someone else doesn't jump in here beforehand, I'll try to help out further tomorrow if you still need it.Good luck David,http://members.rogers.com/eelvish/elrondlogo.gifhttp://members.rogers.com/eelvish/flyurl.gif

[Guest SD Sim]

Hi Elrond,You are correct, it is the GA-7VRXP. Unless I can be convinced otherwise, I plan to trade this board in tonight for an ASUS A7V333, which is in my other computer. I bought the Gigabyte because I liked the features (particularly the dual BIOS), but it gave me nothing but troubles. To be forthright, I was ultimately able to make it through the 3D Mark2001SE benchmark, but just twice. After sitting overnight, it continued to freeze in various stages of the benchmark. Before I took out the board last night, I couldn't even move the mouse when booting up. I read a number of threads on the AMDMB forum for Gigabyte, and tried a variety of fixes. Turning up the Vcore 5% (as many other A7RXP users have found to help) did allow me to get those two successfull benchmarks in...but that was it. I double checked the Vcore just before removing the board, and it was still at 5%. Anyways, I'm pretty certain that this was not a user problem.As for the RAM, I had the BIOS for both boards set up to configure by SPD. In the Gigabyte BIOS (not AWARD, but already forgot who makes it), the SPD showed A CAS latency of 2. The ASUS board showed 2.5 for the Samsung module. When I swapped memory modules around (to see if I had puchased a bad memory module), both boards still had their original CAS settings. Shouldn't the SPD have detected the new RAM and adjusted the settings accordingly? The ASUS board still used the Crucial memory fine, although the benchmark was the same as with the Samsung module (perhaps due to the slower cas settings?).Finally, do you support my decision to go back to ASUS. One reason for the Gigabyte was that I want the ability to use RAID in the future. While my first A7V333 doesn't have RAID, the new one I would like to trade in the GB board for does. I'll check back in later today for your pearls of wisdom. Thanks for your help so far.BTW - I was using the GF4 Ti4600 with the Gigabyte board. I also purchased a 400W Antec PS. Many GB board problems seem to be related to the GF4, perhaps when using an underpowered board. But I think 400W should be enough, particularly since the 300W PS for the ASUS board handles the GF4 just fine.

[Guest]

The Asus board is a very good board, and I think it got better marks then the Gigabyte board. There is an article at Tom Hardware about the 2 boards.Ricky

[Guest]

I don't have extensive experience with the 7VRXP beyond a few hours of play, but the one I did test had few problems running stably in the 180ish FSB range with my normal series of burn-ins (Prime95 and looped 3DMark) - if I remember correctly. I can't remember how much if any I had to boost the various voltages in the test. However thats not much of a recommendation. I have heard from my own users and indeed reviews on the web that its a pretty good board though.Beyond that: I will say it wouldn't be my first choice. While I have always had respect for GigaByte's boards throughout the years, my favorites today are from ABIT and Epox - ASUS in third (or maybe even tied for second if I think hard enough about it). In particular, the ABIT KX7-333R is currently running in my main system at home (I borrowed it from work until the KT400's come out this fall with all the features I really want). The KX7 isn't the most feature rich board for sure (no USB 2.0, FireWire, LAN or sound), it has what I strongly believe to be the best RAID controller on the market: the HighPoint HPT372. I've never liked the Promise RAID controllers as available on the ASUS A7V (and your GigaByte) as much as the HighPoint ones ABIT always uses (along with Epox and Shuttle). Not only are they faster in my experience, but they are much more configurable than the Promise solutions.Otherwise the KX7 is a pretty stock board: six PCI, four DIMM (only three usable without registered DDR though), standard brown/yellow color, etc. Beyond the HPT372, its standout in my eyes is and always will be its stability and overclockability: SoftMenu III is the benchmark that no others have surpassed to date in my opinion.My second choice (until the fall) is the Epox EP-8K3A+. Over the past two years, Epox has steadily grown in my eyes to become on of the best brands on the market: specially for those that wish to push their system harder than most. The 8K3A+ follows the pattern well. It has all the required overclock features and then some (all voltage requirements, etc) and includes the HPT372 for RAID as well. Stability, just like the ABIT, is beyond reproach when pushed. It too, however, is a bone standard stock board: except for the onboard audio (which isn't very good), it misses USB 2.0, FireWire, onboard LAN, Serial-ATA, AGP 8x, etc. Its features are almost identical to the ABIT: 6 PCI, three (fully usable) DIMMs, standard green color, etc.Third (or tied with the Epox) of my preferences is the ASUS A7V. It too has a stellar reputation for stability when pushed. I haven't had extensive experience with this board, but I do know its pretty feature rich: USB 2.0, FireWire, onboard Athlon XP thermal protection (sorely missing from both the current ABIT and Epox boards unfortunately), Promise RAID, onboard audio, etc. While it is a fully decked board and has a great reputation, I've simply found ASUS boards to be hit and miss over the years: some are excellent, some are not. In this case, it definitely looks like a hit.If you are wanting to run your memory at its best, definitely always disable setting by SPD. Those are the manufacturer's conservative settings and recommendations and won't give you near the performance the boards are capable of. With either the ABIT, Epox or ASUS boards (unlike your AMI BIOS based GigaByte), you'll be able to set all four memory timings individually up to 2,2,2,5:Cycle Length: 2 (2, 2.5, 4) - the CAS timing of the SDRAM in terms of clocks.Precharge to Active (Trp): 2T (2T, 3T) - the minimum row precharge time.Active to CMD (Trcd): 2T (2T, 3T) - the minimum CAS to RAS delay.Active to Precharge (Tras): 5T (5T, 6T) - the minimum RAS pulse width.There are other settings such as the command rate (1T, 2T), Burst Length (4, 8), Queue Depth (4, 3, 2), etc. Again, it all depends upon the components in your system weather you'll be able to push this hard (and how high you set your FSB, voltages, timings, etc). With the few components you've pointed out so far however, I'd think you're well on your way to a great push: Corsair CMX3000C2 is my favorite board at the moment so that was a great decision. Its Samsung chips (and the boards design itself) are the best on the market right now.Good luck David and don't hesitate to ask in the future as well if I missed something.Take care,http://members.rogers.com/eelvish/elrondlogo.gifhttp://members.rogers.com/eelvish/flyurl.gif

[Guest PaulL01]

I will just add a little here.......Read what Elrond posted..:)Beyond that just a little more...There are some great memory timing articles on the web and I'm sorry I cant post the links for them right now, but doing a search on the web and educating yourself will go a long way in helping you to get the performance you seek. Try "performance DDR memory timing" or even "XMS3000 memory timing" that should get you going.All the latest Epox 8K3A boards already have the new built-in thermal protection support for the T-Bred XP2200 and beyond, that all the other Kt333 boards don't seem to have yet. :)Sorry not to have time to respond in more detail, work calls got to go...:)

[Guest SD Sim]

Thanks Elrond and Paul,I'm off to trade in the Gigabyte board. I'll take a look at the Abit and Epox boards, but I have to confess that having been burnt with the Gigabyte experience, I'll likely go with another ASUS board since I've been happy with the other two that I have. My goal here is to at least break 10K with 3D Mark2001SE. I'm close (9500), so this should be readily achievable. And if I break 11K, man-o-man. Of course, the one thing I haven't lost sight of is better FS2K2 performance. I'll I want for Christmas is no more of those blasted blurries that suddenly pop into crystal clarity (or at least fewer of them).Paul, your absolutely correct. I do need to educate myself further. I'm working on it, but it often ends up taking more time than I have :-(. Not a great excuse, I know, but it's my excuse all the same.Elrond, thank you as always for the extensively detailed explanations. Every time I read one of your posts I learn something new.