Ansum Full: August 2017

Wednesday, 30 August 2017

What’s The Difference Between SATA And SAS Hard Drives?

Main Differences Between SATA And SAS Hard Drives

SATA stands for Serial Advanced Technology Attachment and SAS stands for Serial Attached SCSI(SCSI Stands for Small Computer System Interface, typically pronounced as “scuzzy”). They’re two types of interface used for transferring data to and from hard drives.

In layman’s terms they are connectors that connect the server motherboard with the hard drives.

Whilst SATA and SAS refer to the data transfer interface they are used to describe two types of hard drive. It is important to note that for the purpose of this post we are referring to traditional ‘spinning’ hard drives as opposed to SSD drives.

Typically the most popular format for SATA drives are 7.2K whereas SAS come in two main types: 10K and 15K. The ‘K’ refers to the speed at which the data platters rotate.

The main difference between them is that SAS drives are faster and more reliable than SATA drives.

The best measure for hard drive speed is IOPS (Inputs Outputs Per Second) which expresses the amount of data that can be written to and read from the drive. The Industry accepted average for 7.2K SATA drives is 80 IOPS whereas 10K offer approximately 120 IOPS and 15K stretch to 180 IOPS. These are averages based on netting out low and intensive worloads.

SAS drives tend to be used for Enterprise Computing where high speed and high availability are crucial such as banking transactions and Ecommerce.

SATA drives tend to be used for desktops, consumer use and for less demanding roles such as data storage and backups.

SAS drives are more reliable than SATA drives. The industry accepted Mean Time Between Failure (MTBF) for SAS drives is 1.2 million hours vs 700,000 hours MTBF for SATA drives.

From a physical perspective the data cables are also significantly different. SATA cables are limited to 1 metre in length and the data and power are separate whereas SAS cables can be up to 10 metres in length with power and data provided through the same cable.

In terms of capacity though, SATA drives win hands down. 3TB SATA hard drives are not uncommon and there are 8TB disk offerings in a 3.5 inch format. Generally though they are most cost effective in the 1TB to 3TB range. SAS drives on the other hand tend to max at around 900GB although the most popular configuration is around 450GB to 500GB.

Other resources:

I hope you found this article useful on the differences between SATA & SAS drives.

Thanks for reading and leave your questions below to keep the conversation going.

https://www.pickaweb.co.uk/kb/difference-between-sata-sas-hard-drives/

Saturday, 26 August 2017

Lenovo G40-30/G50-30 Blue screen

Blue screen occurred during Windows 7 installation (Message: 0x000000A5) – Lenovo G40-30/G50-30

Symptom

Lenovo G40-30/G50-30 may encounter the issues that cannot install Windows 7 or blue screen occurs during Windows 7 setup process with the message of 0x000000A5.

BSOD message: 0x000000A5 (0x00000011, 0x00000008, 0x…, 0x…)

Affected configurations

The above symptom may occur to the following systems:
Lenovo G40-30 Notebook
Lenovo G50-30 Notebook

The above symptom may occur under the following condition:
Running Windows 7 Setup disc / USB key

Solution

Shutdown computer. Press NOVO button, then press Arrow down key to select [BIOS Setup] and hit the Enter key.

Fig.1

Fig.2
If the BIOS version is lower than A7CN27WW, please update BIOS to a7cn48ww or above. You can download the latest BIOS from here. Copy a7cn48ww_32.exe to the root path of your FAT32 format USB disk. Try to boot to your USB disk via Novo button or press F12 while booting. Click a7cn48ww_32.exe to upgrade BIOS to A7CN48WW.
Switch to [Exit] page. Select [OS Optimized Defaults] and set to [Win7 OS].

Fig.3
Select [Load Default Settings] and select [Yes].

Fig.4
Press arrow key to switch to [Configuration] page. Select [USB Mode] and set to [USB 2.0]. After Windows 7 installation, please upgrade USB 3.0 driver and change back USB Mode value.

Fig.5
Press arrow key to switch to [Exit] page. Select [Exit Saving Changes] option and select [Yes] to save the changes.

Fig.6
When Lenovo LOGO appears, press “Fn+F12” to enter “Boot Manager” menu, select the USB key / ODD to setup Windows 7.

Fig.7