Thursday, 9 July 2009

High Density Vs Low Density DDR2 RAM

I've been looking into getting myself some more RAM for my PC. So I looked online and watched eBay for a good price. So I made sure to look out for the exact same as what I have DDR2, PC2-6400, latency timings of 4-4-4-12, speed 800MHz, no ECC and unbuffered. I found an awesome deal with MicroXComputers on eBay, an american company selling 2GB DIMM's for $14 with free postage and packaging. I was well happy. So I bought it, got it all in one piece, threw it in my PC and wondered why it didn't like being in my PC with my two other Crucial 2 x 1GB PC2-6400 DIMM's. Tried it on its own, it worked grand, but in any other mix with the other two DIMM's, it simply wouldn't boot the PC, or it would take an age to get through the POST. I thought to myself, maybe I should have it as a pair instead. But checked around and it shouldn't be a problem.

Anyways, I went back to the listing and noticed this High Density listing it had for that specific DIMM I bought. I spent some time trying to figure out the difference between High Density and Low Density. I found out that Low Density are the better quality DIMM's and the High Density are the cheaper versions.

So you're wondering what are the differences. The difference is to do with how the memory on the DIMM is laid out. Each chip on the RAM DIMM represents a certain amount of memory like 16MB - 256MB. Low Density refers to the density of each of these chips and how they make up the size of the DIMM (1GB = 16 chips of 64Mx8). High Density would have a higher density chip (1GB = 16 chips of 128Mx4). So this must be the reason I can't mix them. I'm assuming the BIOS likes one or the other but not a mix. So I've gone and bought a second one of these high density DIMM's to test around with and get more information out of it.

The easiest way to tell if your DIMM is high density is if there's no name or manufacturer on the DIMM itself. The chips themselves will of course have a manufacturer like Samsung or something. There is no way of telling the difference between the number of these chips on the board as it really all depends on the density of each of the chips and the size of the overall memory on the DIMM itself.

So when looking to buy RAM, make note of the following
1) Speed, ie 800MHz
2) Data Rate, ie 6400
3) RAM type, ie DDR, DDR2, DDR3, RAMBUS (ignoring the older archaic stuff)
4) Density, ie Low or High
5) Latency, ie 4-4-4-12 or for DDR3 7-7-7-20 (otherwise known as the timings)
6) Is it ECC, Registered, fully buffered (slower for servers) or unbuffered.
7) What does your motherboard support?

Here's a quick glossary to the acronyms used above
RAM - Random Access Memory
DIMM - Dual Inline Memory Module
DDR2 - Double Data Rate version 2 (which in its long form is DDR2-SDRAM)
SDRAM - Synchronous Dynamic Random Access Memory
POST - Power On Self Test
BIOS - Basic Input\Output System
MB - MegaByte (not to be confused with Mb which is MegaBit!)
ECC - Error Correction Code

Monday, 6 July 2009

Tales of Monkey Island

Tales of Monkey Island
Monkey Island has returned yet again for the fifth installment of the series. This time sees Guybrush Threepwood battling against the notorious Ghost Pirate Lechuck yet again as he tries to use the secret powers of the monkeys to make himself a god.

This game is split up into five chapters to be downloaded one a month. It's an interesting concept. I wouldn't mind trying the first one, then if I like it, I'll purchase the next one. Below is a link to Tell Tale Games website where you can sign up and download the game. You better sign up fast as today 6th July is the last day to sign up and get the all inclusive offer to get all five chapters, an exclusive DVD slipcase painted by Steve Purcell, the original creator of Monkey Island, a free TellTale Games episode of your choice and access to an exclusive Monkey Island section of TellTale Games website.

Belfast Weekend

Just back from a crazy weekend up in Belfast. It was a crazy booze fueled weekend of night clubs, pubs, watching the Lions beat South Africa 29-9, dancing, hostels and that's just the mild stuff. Other parts of the night included talkin to unionists, nationalists, police. We stayed in a hostel with red, blue and white kerbs across the road from the Royal. There was security threats on the train home from Belfast as well, with the run up to the marching season, things were getting hot up there.

I seriously recommend a trip up North, it really is a beautiful place up there, just don't go wearing any Irish sportswear and keep the accent to a minimum.

You should have come, you could have been shot