# More memory - but how much?

### New operating systems require more computing power and, of course, more memory. In general, the speed of the programs increase when more memory is added - to a certain degree, until reaching a known threshold. We decided to find out what is the acceptable amount of memory for each operating system and where is the threshold which shouldn't be surpassed.

In its times of DOS, users got used to the fact that the memory was always enough. There were some 1 or 2 MByte RAM in the machine, and DOS-programs used only the first 640 kByte of it, and the other part has been lost - if one didn't purchase some memory manager program. Anyway, one had to get these programs additionally, because the 5.0 version of DOS was the first to contain Smartdrv.

After spreading of Windows, the situation has changed. As the applications were liberated from the limitations of the base memory, they were able to use the whole memory in the machine for their purposes. The more memory the higher speed they work.

Today the big Windows-applications love memory very much. Even the normal text-processing and spreadsheet programs have achieved so big sizes that one shouldn't use them on machines with less than 8 MBytes of memory. Managing of pictures require even more power and memory: their minimum requirement is 16 MByte of RAM, if one wants to use them effectively. In general, it's a nice idea to increase the memory to 10 MByte.

### Let's add CHEAP additional power to the machine

Unfortunately PC-dealers don't pay attention to the size of the RAM when they try to achieve as low as possible prices. Even nowadays one can find advertisements in the newspapers that advertise 486/66 multimedia- PCs with 4MB of RAM and with some 200MB hard disk.

If the user doesn't realize that additional memory should be bought, most of the computational power of the machine gets lost. The price isn't too high, the cheapest prices aren't higher than some 750 mk in Finland. If one has a well-known type, he/she may be obliged to pay more, because there are well-known machines and firms with special requirements, which require buying non-common parts and memories.

The memory is the worst place to start saving up, because memory is cheap and its influence on the overall power of the entire system is bigger than that of the processor type/speed. The big amounts of memory also help when there is so much memory, that it can be used to cache the disk, which gives much better performance in the case of the programs that use the disk frequently. The memory of the usual Smartdrv shouldn't be more than 8 MB, but the 32-bit disk access system of Win 3.11 can use even 10 MB cache memories as well.

The other way to make the memory useful is to make a RAM-drive from it. Such RAM-drives, which don't contain moving parts, are far faster than even the fastest hard drives. Anyway, one should remember that these disks aren't permanent, as they forget everything when one switches down the power, so the files should be copied to normal disks before shutting the power down.

### Adding more memory can be hard

Adding more memory to the machine is not always easy. In old machines the problem is that there are restrictions regarding the maximum size of the memory (the maximum can be either 4 or 8 MB) - but nowadays it's almost impossible to find such machines. In the newer models there aren't restrictions, but, when inserting the new 4, or 16 MB SIMM modules, the older ones with far lower capacity should be removed and they couldn't be used any longer. If all the memory is to be changed, such an upgrade can be extremly expensive, because one can't do anything with the old memory moduls. Not to mention the machines with 32- and 72-pin SIMM modules.

Let's look at the case of our test PC, for example. Its mainboard could accept both 32- and 72-pin modules (which is quite unusual with even the newest machines, anyway), but at a time it can use only known collection of RAM modules, and one bank should be always filled. For the entire test, we had to use the following amounts of RAM: 4, 8, 12 and 16, and we had to collect 32 MB of RAM, not only 16!

There are problems that emerge when one wants to install more than 16 MB of RAM. In some machines the speed of the programs can even decrease, when the main memory is increased to 24 MB from 16. This behaviour is caused by quite a lot of things, but the most known is the situation when the processor can access only the first 16MB, and the application is insisting on using the memory area above it, which is the slowest part of all.

This thing can be cured, depending on the machine in question, in the SETUP, where one can increase the usable memory size from 16 MB. Of course, one can add additional processor CACHE to the main board as well, if there is less than 256k of it.

The disk-handlers can also cause problems, if they can't access higher memory areas than the first 16 MB. In this case Windows sees only 16 MB of memory and it can use not even virtual memories to increase it.

#### Different requirements

The size of the required memory size is definitely different in the case of each operating system. The usual Windows can put up with even the smallest memory, in case of running only 16-bit Windows applications (and MS-DOS), and no other applications.

OS/2 requires definitely more memory, because its completely 32-bit world must be lenghtened with the normal 16-bit world of Windows. The tests tell us, in addition, that even if there is quite a big amount of memory in the machine, OS/2 can create temporary virtual memory with the size of even 20-30 MB. Advertisments advertise OS/2 as an operating system which works even on 4MB machines. Even the start of the operating system took five minutes on the 4 MB test machine, and we had to wait for swicthing off the LED some 7 minutes. Even the shutdown-command did not work properly on the 4MB test machine.

Windows NT requires even more, as regards the memory. Even the file of the virtual memory is much bigger, compared to that of OS/2, and it shows that the requirements couldn't be satisfied. And, there is an another problem, regarding Win NT. One can't use Win NT with the same efficiency as a normal Windows or an OS/2, because the file accessing will slow the entire system dramatically, not ot mention the speed of the screen refreshing.

Windows 95 is, in almost every respect, a secret. We could use only a beta version in the test, and it worked much faster than the basic Windows on the lowest configuration memory as well, but the final version is said to have many changes, which may slower the memory management as well.

How much memoy should one have? As regards the test results, one should buy at least 8 MB of RAM when tries to use Windows or Windows 95, while OS/2 requires at least 12 MB RAM and Win NT 16 MB. If possible, these values should be expanded with some 4MB of RAM, and in a multitask/multiuser environment, to meet one's obligations in such a demanding environment, the memory should be even doubled. If one uses the machine as a DTP-machine with megabytes of pictures, while it's on the network etc..., the required amount of memory can't be lower than the sky itself.

If one doesn't have enough money to buy more memory modules, there is one possibility: to use the older versions of the programs he intends to use. For example, the tests of Excel shows us that the older version 4.0 is far faster both on every memory configuration and under every operating systems, than the new 5.0. On the other hand, the oldest 3.0 is the slowest of all, even if theoretically it requires even less memory.

It is clear that the new, promising aspects of the new applications can't be seen. The memory is like he money, which is used when we pay for them.

### Applications show us that much can't be enough

First, we've checked the influence of the memory size on the speed. We've tried all the mentioned memory configurations with the following applications: Word 6, Excel 5, the FoxPro database application, and the DDE-transmission between Access and Word. The test machine was a 486/66 one, the video card was a Cirrus 5428, the disk controller was an Adaptec 5428, and the hard drive a 500 MB one. We've set the diskcache sizes to the recommended size under each operating system. Windows 95 and Win NT have set it absolutely automatically. We've used Win 3.11 with 32-bit disk access and its own cache.

We've put 4,8,12 and 16 MB of RAM to the test machine in the test. We've tried the 24 MB cofiguration as well, to see the influence of this memory size, if we couldn't determine of the effect of the additional memory above 16 MB. Except for OS/2, we've installed every op. system in a TCP/IP-based network, so the protocol has also required some memory for itself.

##### Windows 3.11

###### megatavua/ Mt:a muistia= MB of RAM, sekuntia= seconds

Even in the basic Windows the 4 MB of RAM is not enough for nowadays' applications. To show you the most interesting case, the speed of Excel has been divided by 10 when we increased the memory size from 4 MB to 8 MB. One can't use Word and Access together if he/she doesn't have at least 8 MB memory. On the other hand, the speed doesn't increase, even if we add additional memory to 8MB configurations. The only exception was FoxPro, which was able to store more database in the memory when we increased the RAM size, so its speed can be increased if we don't stop at 8MB memory size. On 4 MB RAM, the entire test took us more than 3 hours!

###### Summarizing: one has to buy at least 8 MB of RAM to use such applications. Optimal solution would be 12 MB.

##### Windows 95 Beta

The Beta version of Win 95 works far better on a 4 MB machine than W3.11. Unlike Win 3.11, it can run even FoxPro in a bearable time. The disk cache size is automatically increased/decreased, and it can be seen on the FoxPro-test, as regards the memory increase from 12 to 16 MB. Anyway, the final memory requirements could be seen only in the final version, when it hits the shelves of the shops.

###### Summarizing: one has to buy at least 8 MB of RAM to use such applications. Optimal solution would be 12 MB.

##### OS/2 3.0 Warp

4 MB of RAM has turned out to be the absolute minimum to run programs under OS/2 Warp. The test gave results as Word - 974 secs, Excel 3- 418 secs. So, if one wants to use Windows-applications under OS/2, he/she has to have at least 8 MB of RAM. When more memory is added to the system, the overall performance of the entire system increases, but, due to the non-demanding cache, this increasement is much more linear than in the other operating systems in the test. On the other hand, OS/2 was the only one op. system in the test which gave us better results when we increased its memory to 24 MB. And the real 32-bit OS/2 applications, regarding the experiences with OS/2's Bonus Pack, also are hungry for memory - even with quite much RAM in the machine, the size of the virtual RAM-file could grow as big as some 10 MB.

###### Summarizing: one has to buy at least 12 MB of RAM to use Windows-applications under OS/2. Optimal memory size is 24 MB.

##### Windows NT - client version

The theoratical minimum of RAM is 8 MB. Every test program worked in such an environment, except for the Access/Word pair. Increasing the RAM influenced the speed visibly in every cases. It was FoxPro that has again produced far better results on bigger memories. When increasing the memory to 24 MB, the speed doesn't get better, only with some seconds.

###### Summarizing: the required minimum is 12 MB of RAM. If one thinks of using Win NT under worse conditions (that is, a more requiring environment), 16-32 MByte of RAM is recommended. If one uses Win NT as a server, the recommended memory size depends on the number of the number of the clients- the more of them the more memory we need.

### Older applications

We've tested the older versions of Excel under several oper. systems to find out whether the new versions are faster than the older ones or the extensions added to the new versions require so much memory that the entire product works far slower.

##### Windows 3.11

The oldest Excel is so small, that its speed doesn't depend on the size of the memory at all. Its character is diametrically opposed to those of newer versions, for which the 4 MB RAM is not enough. The fastest version is 4.0, but if there is enough RAM, 5.0 is also faster than 3.0. It's a great achievement, as the pictures drawn by Excel 5.0 are far more detailed and colorful than those of 4.0 and 3.0, and they requires far more work. In the case of low RAM amounts, the older the version, the faster it runs.

##### OS/2 3.0 Warp

If our machine has only 4 MB of RAM, the wise would run only V3.0. The difference between 8 and 12 MB is quite big in the case of all versions, but after then the differences begin to get smaller. The fastest version was again V4.0, under not only Win 3.11 but also OS/2. The difference between the 12 MB and the 16 MB memory depends on the size of the program. So, in general, V5.0 is the most grateful if we increase the memory.

### 32-bit versions

We've also checked the real 32-bit NT-applications under both Win 95 and Win NT, and their hunger for memory. Under Win NT the speeds are far better when running only 32-bit applications, because in this case Win NT doesn't have to pay attention to the 16-bit emulation. Anyway, its results are far worse than those of the basic Windows, on account of its worse screen handler. Under Win 95, the time required by Word 6 was exactly the same, and the 32-bit Excel's execution time was even worse than that of running the simple 16-bit version. We've run all the four applications on a 16 MB machine.