Ram Memory Information Page 23

Remember that more computer memory boosts performance

Remember that more computer memory boosts performance
Feb 29, 2004

February 29, 2004

When computer manufacturers try to keep prices down, they typically ship systems with less than the optimum amount of memory. Considering that even the cheapest new PCs are more than adequate for Web browsing and light word processing, the practice is understandable. Low-cost systems like Dell's popular Dimension 2400 ($399 with 128 megabytes of RAM) can represent tremendous bargains.

Still, such a memory configuration represents a compromise. Why? Ideally, a computer should keep all active programs and data in solid- state memory, which its processor can access at maximum speed. Absent enough memory, the computer swaps inactive programs and memory from RAM to the hard drive, then automatically reloads material to RAM from disk as it is needed. This kind of disk-based fakery is known as virtual memory, and the space it occupies on disk is called a swap file.

Disk swaps waste time. Think of how long it takes to load your Web browser for the first time in a session vs. how quickly you can switch to it from your word processor once the browser's been loaded. Occasional swaps-to-disk aren't noticeable, but if your disk light flashes constantly, low memory is almost certainly slowing down your PC. It is hard to quantify this precisely, since everyone uses a computer a bit differently, but inadequate memory typically extracts a 30 percent to 60 percent performance penalty. To put it another way, upgrading a memory-deficient PC can, in effect, give it the speed of a unit with a newer processor.

The biggest determinants of how much memory you need are the number and kind of programs you're running. Windows XP, by itself, can squeak by on 128 megabytes of RAM. However, throw in the usual basic complement of Web browser, e-mail program, security software for viruses, adware and spam, and you will see a major performance improvement with 256 megabytes of RAM. Assuming you can afford it, a good conservative choice, with room for future expansion, is 512 megabytes of RAM.

With some applications, you'll need even more memory. Photo retouching is a notoriously memory-hungry process, since programs like Photoshop typically hold two or more copies of a given photo in memory, and you're sometimes working with multiple photos. Multimedia programs for video editing also like lots of RAM, as do games.

Is it possible to have too much memory? Inadequate memory will slow a computer down, but extra memory won't speed a computer up, once excessive disk access is eliminated. So, yes, in a sense it is possible to have too much. Absent the kind of memory- hungry applications described above, you'll usually hit the point of diminishing returns somewhere between 256 and 512 megabytes of memory.

There's a secondary issue with memory, namely when to buy it. Over the years we've gone through a half-dozen generations of memory standards, with each generation packing more memory into a smaller space. At the same time, newer memory is able to communicate with the processor at a faster rate than its predecessor.

In term of prices, this means the newest memory standard tends to command a premium at least in the early part of its product cycle. The previous generation, meanwhile, can be quite cheap as manufacturers tend to overproduce it. Eventually, as demand falls, the standard for the third and fourth generation back are no longer produced, and, because of supply shortages, these too may command a premium. So the best values in memory usually fall in the middle - e.g. if you bought a state-of-the-art new PC, you may want to wait six months or so to buy memory for it.

You can see how this works with current prices from Crucial, one of the bigger suppliers of memory. The sweet spot for price is DDR (double data rate) PC2100, 184-pin DIMMs (dual in line memory module) at $80 for 512 megabytes.

The current state of the art in performance, DDR PC3200, goes for $91.99 per 512 megabytes. Meanwhile, elderly PC133 DIMMs have soared to $92 for just 256 megabytes. According to one of my favorite Web sites that tracks this stuff, anandtech.com, PC2100 prices are gradually rising, as PC2100s are being phased out, and PC3200 memory has fallen steadily in price since it was introduced six months ago.

Which kind of memory can you use? Every computer is different; some can accept more than one kind of memory. Check with the manufacturer of the PC or the motherboard. A related issue: Should you buy two smaller modules or one big one? Generally it is better to keep memory slots free for future upgrades, so try to bundle the memory in one module.

From: http://www.newsday.com/technology/ny-louyx3689613feb29,0,2859354.column?coll=ny-technology-columnists