Author Topic: RAM vendors (Read 372 times)

Tarmac · « **on:** March 13, 2003, 01:28:54 PM »

I've had good experiences with Crucial in the past. Apparently, there's some sort of problem with Crucial's PC2700 (333mhz) memory when it's put into an ASUS A7N8X motherboard. I plan to call Crucial's tech support and ask them about it when I get a chance.

Looking at Samsung memory now. Problem is, Newegg is out of it. Always had good experiences with Newegg in the past. Anyone recommend another online vendor with decent prices and good service, or better yet, share some experiences they've had with different memory manufacturers?

Never plan to overclock... the overclocker memory is out of my price range anyhow.

Thanks in advance.

Vermillion · « **Reply #1 on:** March 13, 2003, 03:24:33 PM »

Try out

http://www.mushkin.com

I've had good experiences with them, and I know Skuzzy likes their memory as well.

Tarmac · « **Reply #2 on:** March 13, 2003, 05:00:02 PM »

Cool thanks. Checking it out.

Staga · « **Reply #3 on:** March 13, 2003, 05:18:05 PM »

I did order my mem-chips from Mushkin and I agree with Verm.

CavemanJ · « **Reply #4 on:** March 13, 2003, 06:40:19 PM »

What kinda problem? Is the A7N8X Asus' nForce2 board?

Tarmac · « **Reply #5 on:** March 14, 2003, 03:21:27 AM »

Yeah, A7N8X is the nforce2 board. Apparently, Crucial's 512 PC2700 sticks had some kind of incompatability with the nforce2 chipset (according to crucial's tech support). It wasn't an every time thing, it was hit or miss. I read that corsair had similar problems as well. Random reboots I think, huge numbers of errors on memtest. Talked to Crucial's tech support today and they said it's fixed on all of their sticks. They've also tested all their in-stock sticks to make sure they're ok. So they don't anticipate a problem unless you order a stick that's been sitting on a shelf somewhere for a few months.

CavemanJ · « **Reply #6 on:** March 14, 2003, 06:45:20 AM »

runnin 2x512 sticks?

Good to hear it's fixed, cause I'm prolly gonna go up to 2x512 in the near future, and usually order direct from Crucial

Pfunk · « **Reply #7 on:** March 14, 2003, 11:10:26 AM »

Kingston HyperX good memory that will kick the toejam out of crucial or mushkin. It is very reasonable price as well PC3000 512MB stick is $80ish 256MB stick is $50. It is CAS 2 latency and has tight timings IF you plan to overclock. Many people that have the ASUS nforce2 or epox 8rda+ board have been having problems with corsair XMS, crucial, and samsung. Not a single person on AMDMB.com have had problems running this memory. Also you can get TWINMOS memory, in case you didnt know corsair XMS is rebadged TWINMOS. But for the $$$$ and performance you cannot beat the Kingston HyperX

http://www.excaliberpc.com for the Kingston

bloom25 · « **Reply #8 on:** March 14, 2003, 11:26:39 AM »

Crucial -> They probably just finally put termination resistors on their PC2700 (DDR333) sticks... (As the spec says you should...

)

jonnyb · « **Reply #9 on:** March 14, 2003, 12:02:32 PM »

Corsair's XMS series low latency memory is worth the price.
Mushkin puts out good stuff too.

Tarmac · « **Reply #10 on:** March 14, 2003, 12:39:32 PM »

Nope, 2 256 sticks. But I didn't know it was only the 512s until I called Crucial. Thought it was all pc2700.

Bloom, what's a termination resistor, and why doesn't Crucial have them if they "should"?

Wish me luck... first time building a computer. Parts should be here monday or tuesday. Woohoo!

bloom25 · « **Reply #11 on:** March 14, 2003, 09:02:49 PM »

A termination resistor is used to prevent signal reflections on a "transmission line" (wire).

I'll try to explain why this is important (without getting too technical)

:

You can think of a signal reflection on a line as an echo essentially.If you have signals reflecting on the memory bus it can cause errors if they are bad enough. This becomes significant when you have several memory modules on the bus and the clock rate is sufficiently high where the signal reflections do not die down when the time comes to read or write data to/from memory.

On an electrical transmission line reflections are minimized when the impedence (resistance) on each end of the transmission line is the same as the transmission line itself. I've seen some memory modules out there that lack termination resistors on the module itself (it cuts costs). This allows data sent to the module by the motherboard northbridge to reflect back to it. If memory timings are aggressive enough (and the nForce 2 can run VERY aggressive memory timings), errors can result.

When buying memory it's not a bad idea to look for the presence of a number of small resistors very close to the bottom of the modules near the contacts themselves. PC2100 DDR does not require it, but the PC2700 spec does include such resistors.

On a Crucial DDR 333 module I looked at a few months ago I noticed no terminating resistors on the data lines on the memory bus. I also noticed that the memory module was only using a 4 layer PCB, which is also not ideal. It is good design practice to place both ground and power planes (solid layers of copper) in the center of a PCB to minimize emitted RF (radio) energy, reduce capacitive coupling between traces, and to keep all grounds at the closest possible potential. With only 4 layers that means all signal traces must run on only 2 layers, which can increase capacitive and inductive coupling betwen traces close to each other (essentially a signal on one line bleeds onto another).

Why Crucial did not include termination resistors is probably because they were not required in the JEDEC PC2100 (DDR266) specification and most early design PC2700 (DDR333) designs used the same PCB (printed circuit boards) as PC2100 modules. When the PC2700 JEDEC spec was finalized last year (in May or June if memory serves) these resistors were added. Crucial modules that are over 4 months old or so may not yet include these resistors.

Edit: Here's something I found: http://www.neoseeker.com/news/articles/headlines/Hardware/1733